CHAPTER 6

COPPER

6.1 Objective

(1) Preparation of complexs compound [Cu(NH3)4]SO4 from the starting material

of copper (II) sulfate pentahidrate compound;

(2) Preparation and identification of khelate complexs compound K2[Cu(C2O4)2]

from complex compound of [Cu(NH3)4]SO4;

(3) Preparation and identification of double salt K2[Cu(C2O4)2] from the starting

material of copper (II) sulfate pentahidrate compound;

(4) Preparation and identification of copper metal, copper (I) chloride, copper (II)

chloride, copper (II) chloride from product of (2) and (3) above and then

become copper (II) sulphate pentahidrate again in a close cycle experiment

that efficience and environment friendly.

6.2 Basic Theory

6.2.1 Characteristic of Copper Tembaga

In nature copper (Cu) is generally obtained from the ore such as copper

pyrite (CuFeS2) and copper glance (Cu2S). Copper has the electron configuration

[Ar] 3d104s1. Chemical properties of copper is closely associated with the

ionization energy, especially the first ionization energy 745 kJ/mol and the second

ionization energy 1956 kJ/mol; heat of atomization of energy and hydration is

relatively low i.e. - 2240 kJ/mol for Cu2+ and - 481 kJ/mol for Cu+; positive

electrode potential and generally have a low reactivity (Greenwood, 1997).

Copper has a single s electron outside the filled 3d skin. This is somewhat

less common with a group stoichiometric alkali except in the formal oxidation

state +1. d-filled skin is much less effective than the noble gases in protecting the

skin s electrons from nuclear charge, so the first ionizing potential of Cu is higher

than the alkali group. Because the electrons in the d skin is also involved in metal

bonding, then the heat sublimation and melting point of copper is much higher

than alkaline

1

-0,12V -0,01V

Copper is used in alloys such as brass and can be dissolved in it both in

gold. Oxidized copper is very slow and occurs only at the surface in the moist air,

and often give the green layer of hidrokso hidrokso carbonate and sulfate (from

CO2 and SO2 in the air).

Nitrate acid soluble copper and sulfuric acid in the presence of oxygen.

Copper dissolves in nitric acid produces copper (II) wherein nitrate acid as an

oxidant. Copper is also soluble in KCN or in solution amionia in the presence of

oxygen, which is indicated by the potential (Sudria, 2002).

Cu + 2 NH3 [Cu(NH3)2]+ [Cu(NH3)4]2+

Copper compounds are generally toxic to most living things, so many of

them are used as insecticides, fungicides and algisida. Examples are compounds

of copper (II) sulfate, CuSO4. Copper (II) sulfate is commercially prepared by

oxidizing copper metal with H2SO4 (Cotton, 1989).

2 Cu + 2 H2SO4 → 2 CuSO4 + 2 H2O

Or oxidize the copper (II) sulfide in the air, according to the following reaction.

2 CuS + 2 O2 → CuSO4

2.2 Senyawa Kompleks Tembaga

Copper compounds are generally toxic to most living things, so many of

them are used as insecticides, fungicides and algisida. Examples are compounds

of copper (II) sulfate, CuSO4. Copper (II) sulfate is commercially prepared by

oxidizing copper metal with H2SO4 (Cotton, 1989).

Ions and simple inorganic molecules such as NH3, CN-, Cl-, H2O forming

ligand monodentat, i.e. an ion or molecule occupies one of the available space

around the central ion in the coordination sphere. Ligands containing two or more

atoms, each of which simultaneously form a bond of two electron donor to the

same metal ion are called ligands polidentate. These ligands also called chelate

ligands. One of the complexes generated in these experiments is the ion

tetraaminacuprate (II).

2

In the wake formula, ion tetraamine cuprate (II) arrows indicate that a pair

of electrons donated by each of the nitrogen ions to copper ions. Charge of a

complex ion is the charge on the ions that make up the complex, for example:

Cu2+ + 4 CN- → [ Cu (CN)4 ]2+

If electrically neutral molecules are involved as ligands in complex form, the

charge on the ion complex remains the same as the charge on the central atom, for

example:

Cu2+ + 4 NH3 → [ Cu (NH3)4 ]2+

Complex formation can be observed from the color change in solution

(Gould, 1995).

Cu2+ + 4 NH3 → [ Cu (NH3)4 ]2+

blue dark blue

In aqueous solution, almost all the salt copper (II) is blue, the color

characteristics of ion coordination complex 6, [Cu(H2O)6]2+ except the famous

copper (II) chloride is greenish because of the complex ion [CuCl4]2- which has

tetrahedral geometry or a square base cations depends on their partner. In dilute

solutions it becomes blue because displacement Cl- ligand by the ligand H2O.

Therefore, if green color to be maintained, in concentrated solution CuCl2 in water

was added Cl- ions by addition of solid NaCl or concentrated HCl or gaseous

[CuCl4]2-(aq) + 6 H2O (l) [Cu(H2O)6]2+

(aq) + 4 Cl-(aq)

green blue

If a solution of ammonia is added to a solution of Cu 2 + ions, the solution turns

blue to dark blue because there are displacement water ligands by ammonia

ligands according to the following reaction.

[Cu(H2O)6]2+(aq) + 5 NH3 → [Cu(NH3)(4-5)(H2O)(2-1)]2+ + 5 H2O(l)

blue dark blue

The addition of hydroxide ions in a solution of copper (II) sulfate (0.1 to 0.5

M) in droping with velocity~1 mL/min resulted in a light blue gelatinous

precipitate salts of copper (II) hydroxy sulfate, [CuSO4.(OH)]2 instead of

Cu(OH)2 according to equation below, (Greenwood, 1997):

[Cu(H2O)6]2+(aq) + SO4

2-(aq) + OH-

(aq) → [CuSO4.nCu(OH)]2(s) + H2O(l)

pale blue

3

Ions of copper (I) when reacted with chloride ions immediately form a

colorless complex ion dichlorocuprate (I), [CuCl2]-. Phase reaction is thought to

take place very quickly thus causing the first reaction stage as follows:

Cu(s) + H3O+(aq) Cu+

(aq) + H2(g) + 2H2O

Cu+(aq) + 2Cl-

(aq) [CuCl2]-(aq)

If the solution is poured into the air-free distilled water, obtained a white

precipitate of copper (I) chloride according to the equation:

[CuCl2]-(aq) → CuCl(s) + Cl-

(aq)

In organic chemistry, dichlorocuprate (I), [CuCl2]- used to convert benzene

into chlorobenzene diazonium chloride according to the Sandmeyer reaction:

[C6H5N2]+Cl-(aq) C6H5Cl(l) + N2(g)

There are five copper chemical reactions involving copper (II) sulfate

(copper vitriol), namely:

If the experiments are designed in a closed chain, the copper vitriol would be

much less necessary and wastes can also be minimized. The circle closed on the

chemistry of copper chain can be described as follows.

4

CuSO4 [Cu(NH3)4]SO4

K2C2O4

K2[Cu(C2O4)2]

CuO + K2CO3

NH3

∆T

Cu

Fe

CuCl2 + KCl

HCl

+ sisa

KOCN

KCu(OCN)3

HCl

CuCl2

CuClsisa

HClO2

CuCl2

O2

NaOH

CuO

H2SO4

+ sisa

sisa

sisa

6.3.1 Chemical and Chemical Aparatus

6.3.1 Chemical Aparatus

No

.

Name Size Amount Information

1 Stiring road - 2 pieces Made of heat resistant glass.

Used for stirring the liquid in

the beaker and also used to

help when the pouring /

5

decantating liquid in the

filtering process process.

2 Burette 25 mL 1 piece The form like ribbed glass

tube and has a faucet at the

end. Size ranging from 5 and

10 mL (microburet) with

scale 0.01 mL, and 25 and 50

mL with 0.05 ml scale.

Serves to remove the solution

with a given volume, usually

used for titration.

3 Porcelain dish - 1 piece Made of porcelain and used

to evaporate the solution.

4 Funnel - 1 piece Made of heat resistant plastic

or glass and has a shape like

a stemmed glass, consisting

of a funnel with a long stalk

and short. How to use it by

putting a filter paper into the

funnel. The funnel serves to

filter the chemical mixture

with gravity. Moreover, it

also used to assist at the

liquid entering into a

container with a narrow

mouth, like a bottle, flask,

burette and so on.

5 Funnel Buchner - 1 piece Essentially the form like

funnels and large-diameter

porous. Made of porcelain,

6

plastic or glass. Useful for

filtering the sample to dry

faster. How to use it by

putting a filter paper whose

diameter is equal to the

diameter of the funnel.

6 Desiccator - 1 piece The form like Stackable pot

filled the bottom two material

dryers, with a removable

hard cover in the cold

because it is coated with

Vaseline. There are two

kinds desiccator: ordinary

and vacuum desiccator.

Vacuum desiccator on the lid

there is a valve that can open

the lid, which is connected by

hose to the pump. Materials

commonly used dryer is

silica gel. Serves as a place to

store the samples must be

free of water, and dried

solids. How to use it is to

open the desiccator lid by

sliding it sideways, then

place the sample and close

the same way.

Silica gel absorbs moisture

can still be blue; if the silica

gel has turned pink then

heated in an oven

temperature to 105 ° C until

7

the blue color.

7 Beaker glass 100 ml;

250 ml

1 piece The form like a tall glass,

with a scale large diameter

along the walls. Made of

borosilicate glass is resistant

to heat to a temperature of

200oC. Used to measure the

volume of solution that does

not require a high level of

accuracy, to accommodate

chemicals, heating the liquid,

the liquid heating medium.

This tool is not a measuring

device (although there is a

scale, but the error large

enough). Used to place the

solution and can also for

heating chemical solutions.

To evaporate the solvent /

solvent or to concentrate.

8 Graduated Silinder

glass

25, 50,100,

250 mL.

1 piece The form like a tall glass

with a scale along the walls.

Made of glass or plastic that

can not stand the heat, so this

tool should not be used to

measure the solution / solvent

in hot conditions. Size

ranging from 10 mL to 2 L.

Serves to measure the

volume of the solution does

not require a high level of

8

accuracy in a certain amount.

9 Erlemeyer Flask 25, 50, 100

mL

1 piece The form like glass whose

diameter gets smaller

growing up with a scale

along the walls. Size ranging

from 10 mL to 2 L. Alt

serves to store and heat the

filtrate solution to

accommodate screening

results, accommodate titrant

(the solution is titrated) in the

titration process. This tool is

not the gauges, although

there is a scale on the glass

tool (erratum large enough).

10 Wacth glass - 3 piece Made of clear glass,

consisting of various

diameter sizes. Serves as a

cover while heating the

sample beaker, place when

weighing chemicals, and a

place to dry solids in a

desiccator.

11 Indicator pH paper - as needed The form like strips which

serves to identify the acidity

of the solution / other

substances. In the box

(container) containing a pH

indicator paper scale degrees

of acidity (pH) 0-14.

12 Lakmus paper - as needed It is an indicator of the form

of small sheets of paper,

9

colored red and blue.

Another indicator that there

is a liquid mass indicator

Phenolphtalein (PP), methyl

orange (MO), and so on. Is a

tool to measure or determine

the level of acidity (pH)

solution.

13 Filter paper - as needed Paper used to filter the

solution.

14 Klem Burett - 1 piece Made of iron or steel to hold

the burette used for titration.

15 Stirer magnetik - 1 piece Magnets are used to stir the

solution.

16 Analitical Balance - 1 piece Used to weigh solid

chemicals.

17 Magnetic heater - 1 piece Square shape, which is used

to heat a substance.

18 Test tube holder Square-shaped jaw. Spring

polished nickel with a

diameter: 10 -25 mm. Tube

clamp serves to clamp the

test tube.

19 Volumetric pipette 5 mL 1 piece Use to take the solution with

appropriate volume with a

label printed on the bubble

(goiter) in the middle of the

pipette. Use propipet or

pipette pump to suck up the

solution.

20 Drop pipette - 3 piece The form like a small pipe

made of plastic or glass with

10

a tapered bottom end and

upper end is covered rubber.

Useful for taking liquids in

small-scale droplets.

22 Statif - 1 piece Made of iron or steel that

serves to enforce the burette,

funnels, separating funnel

and other glassware when

used.

23 Spatula - 2 piece The form like a long spoon

with a flat upper end, made

of stainless steel or

aluminum. Serves to take the

chemical form of solids, and

can be used to stir the

solution.

24 Termometer 0-1000C 1 piece Serves to measure the

temperature of the solution or

other substances.

6.3.2 Chemical

No. Name of

Chemical

Concentration Amount Information

1 Aquades - as needed Liquid, colorless, are

polar. Used as a

universal solvent.

2 CuSO4.5H2O - as needed The form like solid

blue, used as an

ingredient in the

preparation of

[Cu(NH3)4] SO4.H2O.

11

3 Ethanol - 30 mL Liquid, colorless, and is

soluble in water. Used

as a nonpolar medium

in tetraamin formation

of complex compounds

of copper (II) sulfate.

4 HCl - as needed The state is steamy

liquid, colorless, foul-

smelling. Used as a

titrant for titrating

tetraamin copper (II)

sulfate to determine the

concentration of NH3.

5 HNO3 - as needed Liquid, steaming,

colorless to yellowish.

Fumes are very harmful

to the eyes.

6 H2O2 30% as needed Liquid is colorless

liquid harmful to the

eye. Serves as a

powerful oxidizer, the

concentration of 27-

70% or above 70% is

very irritating to the

skin and easily

explode.

7 H2SO4 50% and

concentrated

as needed It is highly acidic,

liquid form and is

corrosive to metals and

as an oxidizer.

8 I2 - as needed The form like purplish

12

black solids, soluble in

water, but easily

soluble in KI, easily

sublimes.

9 K2C2O4.H2O - 8 gram Are solid, crystalline

form, is colorless,

pungent, causing

brittleness when

exposed nails cause

irritation of the mucous

membranes, esophagus,

and gastrointestinal

tract.

10 KI - as needed The form like a white

solid. Used as a solvent

to dissolve the I2.

11 Na2CO3.H2O - as needed Are solid, crystalline or

white powder form.

Serves to produce CO2.

12 NaOH 30% as needed Are solid, the form of

white flakes. Both the

solid and the liquid is

corrosive.

13 Na2SO3(aq) 0,1 M 8,3 mL As a titrant for the

iodometric titration and

the detection of excess

I2 in the determination

of copper

concentration.

14 NH3 Concentrated 20 mL The state is colorless

gas, is irritating to eyes

and skin. Used as a

13

solution that will react

with CuSO4.5H2O

forming Cu(OH)2.

14

6.4 Procedure and Observation Result

No. Procedure Theoritically Observation Experiment Result

5.1 Preparation of [Cu(NH3)4]SO4 . H2O

1. CuSO4.5H2O 5 grams

dissolved in 10 ml aquades

which has been heated in

advance and reheat until all

the copper (II) sulfate

pentahydrate dissolved.

In aqueous solution, almost all the salts of copper (II)

ions are blue that form a complex coordination of 6,

[Cu(H2O)6]2+ :

CuSO4.5H2O + H2O → [Cu(H2O)6]2+ + SO42-

When a solution of ammonia in very little happening

deep blue color, which is caused by the formation of

complex ions tetraaminocuprate (II):

Cu(H2O)6]2+ + 2NH3 + SO42- ⇔

Cu(OH)2.CuSO4↓ + 2NH4+ + 10H2O

If the solution containing ammonium salt (or the

solution is very acid and ammonia used to neutralize it

very much), the precipitation did not occur at all, but the

blue color is formed immediately.

Cu(OH)2.CuSO4↓ + 8 NH3 + H2O → 2[Cu(NH3)4]2+ +

SO42- + 2OH-

CuSO4.5H2O is blue crystal, the mass is

5.0184 grams.

When CuSO4.5H2O dissolved in hot aquades,

not all soluble.

When heated with stirring, the crystals

dissolve in water and produce a blue colored

solution.

2. Added 20 ml of

concentrated ammonia

solution (Cu(OH)2

precipitate will be formed

but will dissolve again) and

Ammonia solution is clear and pungent.

After the solution was added 20 mL of

concentrated ammonia, the precipitate formed

on the bottom of Erlenmeyer.

After stirring, the precipitate dissolves and

15

Dark blue

stir until the solution

becomes clear dark blue.The overall reaction is:

2[Cu(H2O)6]2+ +10NH3⇔2[Cu(NH3)4(H2O)]2+ + NH4+

+ 2OH- + 9H2O

the resulting dark blue solution, as follows

3. While stirring gently, pour

the clear solution into a

dark blue in 30 ml of

ethanol. Let stand for 15

minutes until crystals

formed.

Ethanol is a colorless clear liquid.

After a dark blue solution mixed with

ethanol, is formed dark blue precipitate and

blue solution.

4. The blue crystals After 15 minutes the precipitate separated by

16

precipitated were filtered

by using Buchner funnel.

Wash the crystals three

times, each with 5 ml of

ethanol. Breathe the air for

10 minutes so the crystals

are completely dry.

using Buchner funnel.

After the filtration process is formed a dark

blue) precipitate of [Cu(NH3)4SO4] on filter

paper and the filtrate is clear blue.

While the crystals filtered is dark blue.

5. The remaining reaction

was evaporated in a

vacuum or heating until the

volume is only a few mL,

then concentrated sulfuric

acid dropwise until the

blue color disappeared.

Then the solution was

stored for processing at

substrate 4.

Filtrate screening results are clear blue heated

until the volume just a few mL.

Solution is then poured by concentrated

H2SO4 and dark blue colors are disappear and

then formed light blue solution.

The crystals obtained are 5.4003 grams.

5.2 Preparation of K2[Cu(C2O4)2]SO4 .2H2O

1. K2C2O4.H2O 16 grams

dissolved in a warm

aquades, then poured into a

Tetraamine complex compounds of copper (II) sulphate

is dark blue can be isolated and treated with potassium

oxalate to produce potassium chelate complex

K2C2O4.H2O compound is white crystal.

17

solution made of 5 grams

of [Cu(NH3)4]SO4 . H2O in

12 ml aquades. Dropwise a

concentrated sulfuric acid

until the color is dark blue

turned to blue turkey. (pH

range 4-6)

compounds oxalato cuprate Turkey blue. Reaction as

follows:

[Cu(NH3)4(H2O)]SO4+2K2CO4.H2O

K2[Cu(C2O4)2].2H2O + K2SO4 + NH3

The addition of concentrated sulfuric acid solution

makes the solution changes the color from dark blue to

blue Turkish, is caused by reaction between the

compounds tetraamine copper (II) sulfate with sulfuric

acid. Reaction as follows:

[Cu(NH3)4(H2O)]2+ + 3H2O + 2H2SO4 → [Cu(H2O)4]2+

+ 2(NH4)2SO4

The addition of sulfuric acid will cause protons will join

with NH3 to form NH4+ and ammonia complex will be

damaged. Ammonia molecules displaced by H+ is more

acidic than Cu2+. Then the water molecule will replace

the NH3 to form [Cu(H2O)4]2+. The reasons not to use

HCl because HCl can react with [Cu(H2O)4]2+ forming

[CuCl4]2+. However, [Cu(H2O)4]2+ will never be

completely converted into [CuCl4]2+, because there is an

The mass of K2C2O4.H2O is 8.0085 gram, and

then dissolved in 50 mL aquades.

[Cu(NH3)4]SO4.H2O compound is dark blue

powder

The mass of [Cu(NH3)4]SO4.H2O used is

2,5050 gram, and then dissolved in 6 mL

aquades, it formed dark blue solution.

K2C2O4 clear solution was added to

[Cu(NH3)4]SO4 solution dark formed blue

dark blue solution.

18

intermediate species such as [CuCl(H2O)3]+,

[CuCl2(H2O)2], and [CuCl3(H2O)]-.

After the droped by concentrated H2SO4, the

solution becomes blue turkey, then the

solution was tested byuniversal indicator. The

pH is 6.

2. The mixture was placed in

an ice bath for at least 1

hour or overnight in

refrigerator.

Once placed in ice bath for 1 hour are formed

turkey blue crystals and clear solution.

3. Turkish blue crystals

formed in the decantation,

Crystal decantated and the filtrate cooled

again in ice bath.

19

then washed several times

by ice water.

The crystals which formed were washed by

cold aquades 3 times.

4. The crystals are dried in a

desiccator containing blue

gel. Observed morphology

of the crystals formed. The

remaining reactions are

stored for use at sub. 4.

The crystals that have been washed are

placed in a desiccator so that the crystals

formed are completely dry.

Further crystals obtained were weighed and

the weight of crystal is 5.4003 grams.

5.3 Pyrolysis of K2[Cu(C2O4)2]SO4.H2O

1. The entire preparation of

isolation products in the

substrate 2 placed in a

porcelain dish and heat on

the Bunsen burner. Melting

will begin from the edge of

the cup toward the middle.

Chelate compounds of potassium oxalato cuprate that is

blue Turkey color, if perfectly pyrolyzed will produce

copper (II) oxide, potash (potassium carbonate), carbon

dioxide, and water. As for the reaction:

K2[Cu(C2O4)2] .H2O 2H2O(g)+ K2CO3 + CuO

+ CO2 + 2CO(g)

The isolation product is blue crystal.

The heating is conducted on the heater.

After melted, the mixture is black.

20

2. If all the preparations

melted, keep the Bunsen

burner. Then allowed to

cool at room temperature.

After a heated at long time, all isolation

products turn black resembling sand.

21

3. Changes observed and the

results of pyrolysis

weighed.

The color of products obtained is grayish

black and the weight is 3.0831 grams.

Produk yang diperoleh berwarna hitam

keabu-abuan dan beratnya sebesar 3.0831

grams.

5.4 Acquisition of Copper Metal by Cementation

1. The result of pyrolysis in

substrate 3 was mixed with

20 mL of half concentrated

of hydrochloric acid into a

beaker glass.

The reaction that occurs in this procedure are as

follows:

K2CO3(s)+CO2(g)+ 4HCl(aq) → CuCl2(aq) + 2 KCl(aq)

hijau tua

Cu2+(aq)

+ Fe(s) → Cu(s) + Fe2+(aq)

When the pyrolysis was added by half

concentrated HCl, the mixture becomes light

green and there are air bubbles.

2. The mixture was heated

briefly to produce a dark

green solution.

The mixture is heated and formed dark green

solution.

22

3. This solution is integrated

with the rest of the reaction

in the sub 1 and 2 (the pH

range of the mixture is 1-

3).

The rest of reaction 1 = colorless

The rest of reaction 2 = blue light

When the rest of the reactions 1 and 2 are

mixed with earlier solution, the mixture

remained dark green where the degree of

acidity (pH) = 1.

23

4. Within 30 minutes, added

2.25 gram of fine iron

powder gradually while

stirring.

Iron powder is blackish gray color.

The mass of iron powder used is 1.1251

grams.

After added iron powder, red-brown

precipitate is formed, while the color of the

solution changed from dark green to pale

green, then becomes turbid green, and finally

become white turbid.

5. Added dropwise of

concentrated hydrochloric

acid to maintain pH 1-3

(using a pH meter to

When concentrated HCl is added, the mixture

remained red-brown precipitate, and white

turbid solution.

24

measure the pH of the

solution), then heated

briefly.

The degree of acidity (pH) of this mixture is

1.

6. The mixture is decantated

to separate the brown-red

precipitate of copper

formed. The precipitate is

heated once again with a

little concentrated

hydrochloric acid (iron

must all exist in solution).

Decantation once again and

the united filtrate available.

After decantation I, gained filtrate I that is

yellowish clear.

The precipitate of decantation is red brown

color.

After heated and added concentrated HCl, the

solution is yellow and still there is red-brown

precipitate.

Filtrate of decantation II is yellow.

After the filtrate I and II put together,

forming yellow solution.

7. Added 0.25 gram of iron

powder into the filtrate

which had been unified. If

there is still copper

cementate, do decantation

and repeat the step number

6 until all the copper

cementated (no precipitate

The filtrate was added by 0.2507 grams of

iron.

The filtrate was added by iron powder is

formed red precipitate.

Red precipitate after decantation and

concentrated HCl is added to form a yellow

filtrate.

25

again). When the yellow filtrate combined with the

filtrate I and II is form a mixture of greenish

yellow.

8. Deposition of copper

cementation results are

collected and dried. After

dried, it is weighed.

The precipitate is red-brown and the mass is

0.9574 gram.

To ensure that there is no Fe in the

precipitate, the precipitate washed again by

half concentrated HCl.

After the washing process, the mass of

precipitate was reduced to 0.7075 grams.

mol =

0 ,707563 , 53

=0 , 01mol

9. The residual filtrate The filtrate is stored for use in iron chemistry

26

containing iron ions are

stored for use at the trial

preparation of Fe(acac)3 on

the iron chemistry topics.

experiments.

5.5 Preparation of CuCl

1. CuCl2 solution of substrate

6 was heated in beaker

glass to remove dissolved

oxygen gas.

The reaction that occured in this step is:

2HCl + Na2CO3 → 2 NaCl + CO2(g) + H2O

[CuCl4]2- + 6 H2O [Cu(H2O)6]2+(aq)+ 4 Cl-

[CuCl4]2- + Cu → 2 [CuCl2]-

[CuCl2]- → CuCl + Cl-

Solution of substrate 6 is heated and obtained

bright green solution as well as gas bubbles

arise..

2. Dropped the solution of

concentrated hydrochloric

acid slowly into a solution

of CuCl2 until the pH

reached 1-3.

To the solution is etched by the concentrated

HCl slowly and its pH is obtained 1.

3. Added soda (sodium At the time of adding soda to the solution that

27

carbonate) to the solution

of the tip of spatula to

produce CO2 of protective

atmospheric.

arise gas bubbles occur more (much CO2

protective atmosphere)

4. All the copper powder

produced in the substrate 4

added to the solution, then

slowly stirred while heated

for 30-35 minutes.

Copper powder on the substrate 4 is added to

the solution and stirred slowly and heated for

35 minutes and obtained the solution is

greenish brown.

5. Added (if needed) a little

soda and hydrochloric acid

to maintain pH 1-3 and to

maintain the CO2

protective atmosphere.

Beaker glass covered by

watch glass.

After added by soda and HCl, the solution is

become blackish green (hijau lumut).

6. During heating, evaporate

75 mL of water from the

solution, then cool the rest

of the solution at a

After heated, cooled and added H2SO4 formed

yellow solution and not obtained precipitate

yet.

28

temperature of 0oC and

added 3 mL of sulfuric acid

(to stabilize the CuCl from

oxidation by oxygen in

air).

7. The solution is filtered in

ice water (it will separate

the insoluble CuCl from a

solution of [CuCl2]-) and

decantation white

precipitate formed

immediately, then wash the

precipitate by little ethanol.

The solid obtained was

dried in the desiccator.

After cooled is formed green solution and

there are precipitate.

Further decantation is obtained pale yellow

precipitate and light green filtrate.

After the precipitate was washed by ethanol

is obtained white precipitate.

8. If the rest of the solution is

colorless, throw down the

sink. If it still blue, it

means that it still contains

Cu2+ ions and need to be

addressed further. Blue

The blue filtrate is stored for the next step.

29

solution was stored for

further processing at

substrate 8.

5.8 Re-production to Produce Vitriol Copper

1. The entire preparation of

CuCl results in substrate 7

is placed in the open air

until the color is green,

then suspended with 20 mL

of dilute hydrochloric acid.

The suspension was put

together with the remaining

blue solution at substrate 7.

These mixture then flows

through the oxygen gas

until the solution become

The reaction that occured in this step is:

2 CuCl 2 HCl + 1/2O2 → CuCl2 + H2O + Cl-

2CuCl + H2O2 + 2HCl→ 2CuCl2 + 2H2O

CuCl2 + NaOH + Na2CO3 → CuO + CO2 + NaCl +

H2O

CuO + H2SO4 → CuSO4 + H2O

After placed in the open place, the white

precipitate of CuCl that is preparation results

is turned to green and after the addition of

dilute HCl is form green suspension.

When the suspension combined with the

residual filtrate and flowed by oxygen gas,

the color of the solution is become lighter.

30

bright green.

2. Added a few drops of 30%

hydrogen peroxide into the

mixture. Then added

dropwise the solution of

30% sodium hydroxide to

pH range is 4-5.

After added H2O2 30%, the solution is

remained bright blue.

When NaOH solution was added is arise

black precipitate, but immediately

disappeared and the pH = 5

3. Heat the solution with a

small flame, and then

added by little powdered of

Na2CO3 solution until the

pH reached 11-12. By the

heating the precipitate will

form black CuO. The

precipitate which formed

was filtered and washed by

aquades. Colorless filtrate

can be discarded into

landfills for the remaining

solution containing

After the addition of Na2CO3 powder until the

pH = 11, is formed a brown solution.

After heated, from the brown is arising black

precipitate of CuO.

Then filtered, obtained black precipitate and a

colorless filtrate.

31

halogen.

4. Black precipitate of CuO is

inserted in beaker glass,

then added dropwise 50%

sulfuric acid solution until

the precipitate of CuO still

a little and decantation

immediately.

At the time the black precipitate of CuO was

added by H2SO4 50% is formed blue solution.

When the precipitate is still a little, soon

decantation.

5. The solution is cooled at

room temperature resulting

the crystallization process.

To enhance crystallization,

place the solution in a

refrigerator overnight.

After cooling for 1 week blue crystals is

formed.

6. Crystals formed and the

remaining solution is

decantation. The crystals

are washed by ice water

and filtered. Then the

crystals are dried in a

Obtained crystals and blue filtrate.

32

desiccator.

7. Copper vitriol crystals that

formed were weighed and

compared with copper

vitriol that has been used in

this experiment cycle.

The crystal vitriol copper obtained is 0.1017

grams.

8. If the residual solution still

contains copper ions, the

remaining solution is

stored.

The remaining filtrate obtained is very little

and stored for recycling.

33

6.5 Discussion

6.5.1 Preparation of [Cu(NH3)4]SO4

In this cyclical chemical copper experiment, was used compound of copper (II) sulfate

anhydrous starting material as much as 5.0184 gram. CuSO4.5H2O compounds are difficult to

dissolve in aquades at normal and low temperatures, so aquades that is used to dissolve the

compound of copper (II) sulfate anhydrous must be heated first. To enhance dissolution of

copper (II) sulfate anhydrous in aquades, then the mixture was stirred while heated in an

electric heater. The solution is then added to 20 mL of concentrated ammonia. At the

beginning of the addition, then the precipitate formed after all of concentrated ammonia is

added to a solution of CuSO4, the precipitate was dissolved again. The precipitate that had

formed before the deposition of the Cu(OH)2. At the dissolution of CuSO4.5H2O is occurred

reaction as follow :

CuSO4 . 5 H2O(s) CuSO4 (aq)

When CuSO4 solution was added by concentrated ammonia is occurred reaction as follow:

CuSO4 (aq) + NH4OH → Cu(OH)2 (s) + (NH4)2SO4

The precipitate Cu(OH)2 which is formed is not stable, so it can be dissolved again. The

addition of ammonia can shift the equilibrium, which causes the formation of complexes [Cu

(NH3)4]SO4 with the following reaction.

CuSO4 (aq) + 4NH3 (aq) → [Cu(NH3)4]SO4 (aq)

After stirring was stopped formed clear dark blue solution. At the time of adding

concentrated ammonia is still being done in hot conditions, in order to complete dissolution

occurred (no sediment). Complex solution which has been obtained is then poured into the

Erlenmeyer flask containing 30 mL of ethanol. The reasons complex solution was dissolved

into ethanol because a complex compound is not soluble in nonpolar solvents, namely

ethanol, so it can form complexes precipitate tetraamin copper (II) sulfate, [Cu(NH3)4]SO4 (s)

which is the color is blue

If the solvent that is used is not nonpolar solvent but polar solvent then it can lead to the

formation of ammonium sulfate. This situation can occur because it is caused by the

34

H2O

positively charged ammonium and negatively charged of sulfate, so that when joined will

form a compound of ammonium sulfate.

A mixture of precipitate [Cu(NH3)4]SO4 with its solution then allowed to stand for 15

minutes. This has purpose to be a perfect crystallization. The precipitate then separated using

a Buchner funnel. Function using a Buchner funnel in the process is to accelerate the filtering

and minimize liquid content in the precipitate.

Crystalline precipitate filtered and washed with ethanol which aims to remove

contaminants, in order to obtain pure crystals. The result of filtering process (filtrate) was

mixed with ethanol washing results. Then evaporated until the volume is only a few mL. It

aims to make the ethanol that contained become evaporate. Indicators as a sign that ethanol

has evaporated is the color of the filtrate from clear blue to turbid blue. Furthermore, the

turbid blue solution was added concentrated sulfuric acid as much as 5 drops, so the solution

becomes colorless solution, because the rest of the bases are still present in the complex Cu

filtrate has been neutralized by sulfuric acid. Crystalline precipitate obtained dark blue and

then dried in an oven. When weighed mass of crystal obtained was 4.4590 grams. Then from

this experiment is obtained yields crystal of [Cu(NH3)4]SO4 was calculated as follows:

Mass of CuSO4.5H2O = 5,0184 gram (molar mass = 249,68 g/mol)

Mol of CuSO4.5H2O =

5 , 0184 gram249 , 68 gram /mol

= 0,02 mol

Volume of NH3 = 20 mL (Mr = 17 g/mol)

Density of NH3 = 0,91 g/mL

mol of NH3 = (20 x 0,91) / 17 = 1,070 mol

Mass of [Cu(NH3)4]SO4. H2O theoritically = 4,91 gram that was obtained from

calculation process as below:.

CuSO4.5H2O + 4 NH3 [Cu(NH3)4]SO4. H2O + 4 H2O

m : 0,02 mol 1,07 mol - -

35

b : 0,02 mol 0,08 mol 0,02 mol 0,08 mol

s : - 0,99 mol 0,02 mol 0,08 mol

so, mass of [Cu(NH3)4]SO4. H2O = mol x molar mass

= 0,02 mol x 245,5 g/mol

= 4,91 gram

In this experiment was obtained 4,3950 gram of [Cu(NH3)4]SO4.H2O, so the percentage yield

is :

% yield =

mass of exp erimentmass theoritically

x 100 %

=

4,3950 4,91

x 100 %

= 89,51%

6.5.2 Preparation of K2[Cu(C2O4)2]SO4 . 2H2O

In the preparation of K2[Cu(C2O4)2]SO4.2H2O used half of the mass that is in

substance the procedure, which is 2.5050 grams of [Cu(NH3)4]SO4.H2O dissolved in 6 mL

aquades, while the weight of K2C2O4.H2O used as much as 8.0085 which is dissolved in 50

mL aquades. When K2C2O4.H2O dissolved in warm aquades lukewarm, formed a white turbid

solution and the K2C2O4.H2O crystal which is difficult soluble in cold aquades, so it needs to

be warmed first so that the crystals dissolve completely. Powder of [Cu(NH3)4]SO4. H2O

dissolved in aquades produce a dark blue solution. When both solutions are mixed together,

formed a dark blue solution.

Then the dark blue solution was added by 30 drops of concentrated sulfuric acid, so

the color of the solution becomes blue Turkey. The purpose of the addition of sulfuric acid to

acidify the solution. When the pH of the solution measured, the pH is 6. The reaction that

occurs between the solution of [Cu(NH3)4]SO4.H2O with K2C2O4.H2O solution is as follows.

[Cu(NH3)4]SO4. H2O + 2 K2C2O4.H2O K2[Cu(C2O4)2].2 H2O + K2SO4 + NH3

36

Turkish blue solution then was cooled in an ice bath, so that the formation of crystals

becomes more optimal. After cooling in an ice bath crystals obtained the blue turkey in a

light blue solution. The next step, the crystal was decantated and washed 3 times with cold

aquades. The washing process has a purpose to eliminate the impurities that exist in these

crystals. The light blue solution as the result of washing was mixed with the filtrate obtained

in the process of decantation.

Pale blue color filatrate

The filtrate that was obtained still contains complex K2[Cu(C2O4)2]SO4.2H2O, so it must

be dried in a desiccator. Mass of crystals were obtained is 5.4003 grams, while the filtrate

obtained was stored for the next experiments.

6.5.3 Pirolisis K2[Cu(C2O4)2]SO4. H2O

Crystal of K2[Cu(C2O4)2]SO4.H2O that was obtained was placed in a porcelain dish, then

heated. After heated, initially blue crystal turned into blackish brown, due to a chemical

breaking structure into the gas phase. The black color formed is the color of CuO. Chelate

compounds of potassium oksalato cuprat which is has blue Turkey color, if perfectly

pyrolyted will produce copper (II) oxide, potash (potassium carbonate), carbon dioxide, and

water, such as the following reaction.

K2[Cu(C2O4)2] .H2O 2H2O(g) + K2CO3 + CuO + CO2 + 2CO(g)

37

∆

heated

The crystal as the result of pyrolysis was weighed and the mass was obtained is 3,0831 gram.

6.5.4 The acquisition of Metals Copper cementation

Crystal results of pyrolysis that was obtained with mass 3.0831 grams was added with

half-concentrated HCl (6M) produced a green solution. The purpose of the addition of HCl is

to react the results of pyrolysis into CuCl2 and KCl. The green color solution is CuCl2. In

addition, when the addition of half-concentrated HCl also appear bubbles gas which indicates

the formation of CO2. Thus, the addition of HCl was carried out in acid room. As the

reaction, are as follows:

CuO(s) + K2CO3 (s) + 4 HCl (aq) → CuCl2(s) + 2 KCl + CO2(g) + 2H2O (g)

The solution was heated in order to accelerate the reaction and remove the water present

in the solution. Once heated, the solution became dark green. The solution of this reaction,

then mixed with the rest of the reaction in the sub 1 (colorless solution) and the rest of the

reaction sub 2 (blue solution), formed a light blue solution. The mixing is aimed to obtain Cu

that may still remain in the previous reaction. When checked the pH of the mixture is 1.

38

Crystal of K2[Cu(C2O4)2]SO4. H2O Color of crystal turns become brown-black

The result of pyrolysis

In the solution that has been formed, added as much as 1.1251 gram of iron powder.

The addition of iron powder done little by little, which aims to iron powder can be dissolved

completely in solution. Stirring was done by using a stirring rod, because if done using

magnetic Stirrer, iron will stick to the magnetic Stirrer, considering the iron can be drawn by

the magnetic field of the magnetic Stirrer. When iron powder was added, the solution formed

a yellowish green and brick red precipitate is formed at the base of the beaker. The reaction

that occurs when the addition of Fe on copper are as follows.

CuCl2(aq) + Fe (s) → Cu(s) + Fe2+(aq)

Yellowish green solution and brick red precipitate

Yellowish green solution then was heated with a purpose to perfecting the precipitate

formed. Furthermore, the precipitate formed was decantated, obtained the brick red

precipitate and green solution. Precipitate of brick red was dropped by HCl and heated

slightly. The addition of HCl is intended to Fe2+ which is likely still contained in the

precipitate of Cu can be dissolved in HCl to form a yellow FeCl2. With the addition of HCl,

has purpose to dissolve the iron by produce iron (II) salts and hydrogen gas.

Fe + 2H+ → Fe2+ + H2 (g)

39

Filtrate sub 3.1 Filtrat sub 3.2 The solution after heated

Milk blue solution

Fe + 2HCl → Fe2+ + 2 Cl- + H2 (g)

After addition of HCl and heating process, was formed a little yellow FeCl2. All the

filtrate obtained was mixed and re-added 0.2507 grams of iron powder until no more copper

is formed. Copper precipitate was collected and washed with half concentrated HCl. The

reason the use of half-concentrated HCl (not concentrated HCl), because if using

concentrated HCl maybe copper can dissolve in HCl. When weighed, was obtained mass of

copper precipitate is 0.7079 grams. While the residue of the reactions (green solution) was

stored for iron chemistry topic.

The precipitate copper before it is washed with 6M HCl

The res idue of the cementation reaction (green solution)

The calculation is done using the mass yield of [Cu(NH3)SO4.H2O. Because, in

experiments that was conducted on the pyrolysis was not carried out the weighing of the

product obtained. Besides that, in pyrolysis was obtained precipitate containing the two

products of CuO(s) dan K2CO3(s).

40

Mass of [Cu(NH3)SO4.H2O = 4,91 gram ; Mr = 245,5 g/mol

Mol of [Cu(NH3)SO4.H2O = 4,91/245,5 = 0,02 mol

Reaction that is occurred is as follow.

[Cu(NH3)4]SO4. H2O + 2 Na2C2O4.H2O K2[Cu(C2O4)2].2 H2O + K2SO4 + NH3

mol of [Cu(NH3)SO4.H2O = mol Cu

so, mass of Cu theoritically = mol Cu x Mr C

= 0,02 mol x 63,5 g/mol

= 1,27 gram

In thos experiment was obtained 0,7079 gram of Cu, so that can be calculated % yield as

follows.

% yield = mass of experimentmass theoritically

x 100 %

= 0.7079 gram

1,27gramx 100 %

= 55,74%

6.5.5 Preparation of CuCl2 solution

CuCl2 compounds in chemistry copper experiment was not made through the

preparation of KCu(OCN)3, but was made by dissolving crystals of bright green CuCl2.2H2O

in aquades. When the crystals are dissolved in aquades CuCl2.2H2O, was obtained bluish

green solution.

Preparation of CuCl2 solution is adjusted to the amount of copper obtained. The

amount of copper vitriol obtained in this experiment is 1,0215 grams. The calculation is as

follows.

Mol Cu =gram CuMr Cu

= 0 ,707963 ,5

= 0 , 01 mol

41

Based on the reaction equation :

Cu(s) + CuCl2(aq) → 2CuCl

So, mol of CuCl2 that is needed is:

mol of K2C2O4= coefficien of CuCl2

coefficien of Cux mol Cu

=11

x 0,01 mol

= 0,01 mol

So, mass of crystal CuCl2.2H2O that is needed:

Mass of CuCl2.2H2O = mol x Mr CuCl2.2H2O

= 0,01 mol x 170,48 gram/mol

= 1,7048 gram

So, mass of CuCl2.2H2O that is required is 1.7048 gram and then dissolved in 50 mL

aquades. For the next step, this solution was heated and obtained greenish blue solution.

6.5.6 Preparation of CuCl

In experiment of preparation of CuCl was used CuCl2 solution. When the CuCl2 solution

was heated, bluish-green solution formed. The purpose of heating is to remove oxygen gas

which is dissolved in the solution (evaporate into the air), so it does not interfere the next

processes. When measured the degree of acidity of the solution, the pH is 1, so do not do the

addition of concentrated HCl, because the addition of concentrated HCl has purpose to make

the solution becomes acidic conditions (pH = 1).

CuCl2 solution that formed was added by a spatula tip of Na2CO3. The addition of

Na2CO3 were conducted to form a CO2 protective atmosphere that can prevent the entering of

oxygen from the air into the system which can oxidize copper (I) into copper (II). When the

addition of sodium carbonate, the gas bubbles formed in the solution. Bubbles is a CO2

protective atmospheric produced from the decomposition of Na2CO3 as follows.

Na2CO3 → 2 Na+(aq) + CO3

2-(aq)

42

CO32- ions that was formed will further react with Cu+ to produce Cu2CO3 which then

reacts with H+ from the addition of HCl to form H2O and CO2. The reaction that is occurres

is as follows.

2Cu+ + CO32- → Cu2CO3(s)

Cu2CO3 + 2H+ → 2Cu+ + H2O + CO2(g)

Into the solution, then added all the Cu powder produced at the experiment sub 3.4.

After the copper powder was added, the solution was then heated for 30-35 minutes. The

addition of copper powder led to the solution became brown. Heating is done so that all the

powder can be dissolved perfectly or excellent (no sediment Cu powder that has not

dissolved). This heating is maintained, to keep warm so that Cu+ has formed no longer be

oxidized become Cu2+. The reaction is:

Cu2+(aq) + Cu(s) 2 Cu +

(aq)

Solution that has been formed, was added by baking soda which is has purpose to form

a protective CO2 atmosphere. HCl solution was not added, because its acidity is enough acid

(pH 2). Solution had been added the baking soda, then heated and covered with a watch glass.

It is intended that no oxygen that goes into the solution, because it can oxidize Cu+ to Cu2+

again.

During the heating process was evaporated about ¾ mL of solution. Evaporation

process is intended to keep CuCl2 solution from insistence of Cl- ligands by water ligands

according to the following equation.

[CuCl4]2- + 6 H2O [Cu(H2O)6]2+(aq) + 4 Cl-

After volume of solution about ¼ mL of the initial volume, the green solution was

placed in an ice bath and concentrated sulfuric acid was added. The purpose of the addition of

H2SO4 is to stabilize the CuCl that was formed from the oxidation by oxygen from the air.

After cooling a white precipitate formed and the solution is pale yellow color.

The precipitate obtained was separated by decantation. The precipitate obtained is very

little, because the copper powder produced in the previous experiments is very little that is

0.7079 grams. The filtrate as the result of the decantation was heated again to make the water

evaporated so that the solution will be saturated. This white precipitate is CuCl, which is then

43

washed with a little ethanol and decantated. After decantated and washed with ethanol gained

a little white precipitate CuCl which is insoluble in [CuCl2]-. The reaction that occurs is as

follows.

[CuCl2]- → CuCl + Cl-

The precipitate was dried in a desiccator, while the remaining solution is pale yellow stored

for the next experiments.

6.5.7 Recycling To Produce Copper Vitriol

The preparation results of CuCl preparation will be recycled to get copper vitriol. The

solid CuCl preparation results placed in an open place, so that occurred oxidation process of

Cu+ to Cu2+. This is because the presence of oxygen from outside air. Indications of this

oxidation process is the change color of CuCl solid from white to green.

Then the solid was suspended with 20 mL of dilute HCl. Next add the rest of the

reaction of sub.7, formed a colorless solution older. This solution was then added H2O2 30%

as much as 4 drops which aims to enhance the reaction CuCl become CuCl2, (all Cu+ can be

oxidized to Cu2+). Here is a reaction that occurs.

CuCl + H2O2 → CuCl2 + H2O

After that, the solution is was heated with a little fire, which is then added powder of

sodium carbonate while still heated. With the addition of sodium carbonate, the color of

solution turns brown and the gas bubbles formed on the surface of the solution. These gas

bubbles are CO2 gas produced from the reaction as follows:

CuCl2(aq) + Na2CO3(s) CuO(s) + NaCl(aq) + CO2 (g)

The addition of Na2CO3 was done until the pH range 11-12. Therefore, the addition of

Na2CO3 into the solution still being done while still heated with a small fire. After some time

the addition of Na2CO3, pH of the solution was measured again using a universal indicator

and obtained pH = 11 and formed a brown solution. Then the solution was kept heated to

44

∆

make the black precipitate of CuO formed. At this heating, the solution is brown at first,

gradually turns into a black and a black precipitate is formed which is precipitated of CuO.

Black precipitate then separated by filtering process. The filtrate is colorless, it can be

safely removed to a laundry tub. Further precipitatewhich are still left in thefiltering paper

washed with aquades to remove the impurities. Black precipitate was transferred to a beaker

and added 50% sulfuric acid. The purpose of this is the addition of sulfuric acid to form

copper sulfate to the reaction as follows.

CuO(s) + H2SO4(aq) → CuSO4(aq) + H2O(i)

After the sulfuric acid was added, forming a blue solution. Then the solution was cooled in a

refrigerator for one week to obtain CuSO4 crystals (copper vitriol).

CuO precipitate after the addition of sulfuric acid

(formed blue solution)

The crystals that was obtained in this experiment is 0.1017 grams and the filtrate results of

decantation in the form of blue-colored solution. Then the filtrate was stored for next

experiment recycling.

6.6 Closing

6.6.1 Discovery

45

6.2 Conclusion

Based on the observation result and discussion can be concluded that :

1. Complexs compound [Cu(NH3)4].SO4 can be made by reacting CuSO4.5H2O with

concentrated NH3 according to the following reaction:

CuSO4.5H2O + NH3 [Cu(NH3)4].SO4 + 5 H2O

In this experiment was obtained [Cu(NH3)4].SO4 amount 4,4590 gram by percentage

yield = 90,81%

2. Complexs K2[Cu(C2O4)2].2 H2O can be made by reacting [Cu(NH3)4].SO4 with

K2C2O4 according to the following reaction:

[Cu(NH3)4].SO4 .H2O(aq) + K2C2O4(aq) K2[Cu(C2O4)2].2 H2O

Blue Colorless Dark Blue

3. Pirolysis of K2[Cu(C2O4)2].2 H2O producing CuO ,K2CO3 and also H2O.

4. Copper can be obtained from cementation process by reacting the result of pyrolysis

with HCl 6 M according to the following reaction:

CuO (s) + K2CO3 (s) + 4 HCl (aq) CuCl2(s) + 2 KCl(aq) + CO2(g) + 2 H2O (g)

Amount 0,7079 gram of Cu was obtained from cementation process, and the

percentage yield = 55,74%.

46

5. CuCl can be obtained by reacting CuCl2 with HCl producing CuCl according to the

following reaction:

CuCl2 + Cl- CuCl + Cl2

Then was added by sodium carbonate producing CO2 gas according to the following

reaction.

2 Cu2+ + CO32- Cu2CO3

Cu2CO3 + 2 H+ 2 Cu2+ + H2O + CO2

After that was added by Cu powder from procedure 4, is occurred reaction as follow:

2 Cu2+(aq) + Cu(s) 2 Cu+

(aq)

[CuCl4]2- + 6 H2O [Cu(H2O)6]2+(aq) + 4 Cl-

[CuCl2]- → CuCl + Cl-

From the reaction was otained white crystal of CuCl

6. Recycling of copper vitriol was done by reacting CuCl2 with Na2CO3 produce CuO

which is reacted with H2SO4 produces CuSO4. In this experiment was obtained as

much as 0.1017 gram of copper vitriol.

6.3 Suggestion

47

48