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JOM CHEMISTRY A1
TOPIC: Salts
Name: …………………………………………. Date Received : …………………
Form: …………………… Date Completed: ………………..
Qualitative Analysis of Salts
In the qualitative analysis of salts, we need to identify the ions that are present in salts. This can be done by analysing their physical and chemical properties.
Observations on the physical properties of salts
1. Colour and solubility in water
Certain physical properties of salts such colour and solubitity in water are observed to help us infer certain cations and anions that are present in salts.
Table shows the colour of salts in solid , in aqueous solution and the solubility of salts in water
Salt Colour in solidSolubility in water
Colour in Aqueous solution
1. Ammonium chloride NH4Cl
2. Ammonium nitrate NH4(NO3)2
3. Calcium carbonate CaCO3
4. Calcium nitrate Ca(NO3)2
5. Magnesium sulphate MgSO4
6. Magnesium carbonate MgCO3
7. Zinc sulphate ZnSO4
8. Zinc nitrate Zn(NO3)2
9. Lead(II) chloride , PbCl2
10. Lead(II) sulphate , PbSO4
11. Lead(II) carbonate , PbCO3
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What is Qualitative analysis?……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………...
JOM CHEMISTRY A1
12. Copper(II) chloride , CuCl2
13 Copper(II) sulphate , PbSO4
14. Copper(II) carbonate , PbCO3
15. Iron(II) sulphate , FeSO4
16. Iron(III) chloride , FeCl3
17. Sodium nitrate , NaNO3
18, Sodium carbonate , Na2CO3
19. Potassium nitrate , KNO3
20. Potassium carbonate , K2CO3
Table shows the colour of different cations in solid form and in aqueous solution
Observation Inference
Blue solution
Pale green solution
Yellow/Yellowish-brown/brown solution
Green solid
Brown solid
White solid
Colourless solution
Table shows the solubility of different types of salts in waterCompounds Solubility in water
Sodium saltsPotassium saltsAmmonium salts
Nitrate salts
Chloride salts
Sulphate salts
Carbonate salts
2. Tests for gases
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Gases are often produced from reactions carried out during laboratory tests on salts. By identifying the gases evolved,it is possible to infer the types of cations and anions that are present in a salt.
Table shows the test and the result of different gases
Gas Test Result
Oxygen gas, O2
Hydrogen gas , H2
Carbon dioxide gas , CO2
Ammonia gas, NH3
Chlorine gas, Cl2
Hydrogen chlorine gas , HCl
Sulphur dioxide gas , SO2
Nitrogen dioxide gas , NO2
3. Action of heat on salts
Effect of heat on carbonate saltsCarbonaate salt Colour of salt before
heating Colour of residue Effect on lime water Hot cold
Copper (II) carbonate, CuCO3
Zinc carbonate , ZnCO3
Lead(II) carbonate, PbCO3
Sodium carbonate, Na2CO3
Calcium carbonate, CaCO3
Potassium carbonate, K2CO3
Magnesium carbonate, MgCO3
Effect of heat on nitrate saltsNitrate Salt Colour of salt before
heating Colour of residue Test on gases liberated Hot cold
Copper (II) nitrate, Cu(NO3)2
Zinc nitrate, Zn(NO3)2
Lead(II) nitrate, Pb(NO3)2
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Sodium nitrate, NaNO3
Calcium nitrate, Ca(NO3)2
Potassium nitrate, KNO3
Magnesium nitrate, Mg(NO3)2
Iron(II) nitrate, Fe(NO3)2
Iron(III) nitrate, Fe(NO3)3
The table shows the comparison of the effect of heat on carbonate and nitrate saltsMetal Effect of heat on carbonate salt Effect of heat on nitrate saltPotassiumSodiumCalciumMagnesiumAluminiumZincIronTinLeadCopperMercurySilverGold
Most sulphate salts are not decomposed by heat. Only a few sulphate such as iron(II) sulphate,zinc sulphate and copper sulphate decompose to sulphur dioxide or sulphur trioxide gas when heated.
All chloride salts are stable when heated except ammonium chloride. Ammonium chloride sublimes and decomposes to produce ammonia gas and hydrogen chloride gas.
The table shows the deduction of the types of ion present based on the gas produced
Type of gas produced Type of ion present
CO2
O2
NO2
SO2
NH3
Do it Yourself !
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JOM CHEMISTRY A1
1. State three examples ofa) soluble salts b) insoluble salts
2. Which of the following salts is soluble
3. Identify the gas that turns moist red litmus paper blue
4. Gas X has the following properties
Gas X is ___________________________________________
5. Heat +
Colour of metal oxide X is yellow when hot and white when cold. Gas Y turns lime water milky.
a) Name gas Y ___________________________________________________b) Name metal oxide X ____________________________________________c) Name salt P __________________________________________________d) Write an equation to represent the action of heat on salt P
6. A sample of copper(II) nitrate, Cu(NO3)2 was heated strongly. Write down the expected observation.
Qualitative Analysis of SaltsTests for anions
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Lead(II) chloride Sodium carbonate
Calcium sulphate Barium sulphate
Colourless Acidic gas Turns lime water milky
Salt P Metal oxide X Gas Y
JOM CHEMISTRY A1
Reagent / Condition Observation Anion Ionic Equation (if any)
2 cm3 the unknown solution + dilute hydrochloric acid / nitric acid / sulphuric acid pour into a test tube gas liberated is immediately bubbled through lime water.
2 cm3 of nitric acid + 2 cm3 of the unknown solution pour into a test tube + 2 cm3 silver nitrate solution
2 cm3 of dilute hydrochloric acid / nitric acid + 2 cm3 of the unknown solution pour into a test tube + 2 cm3 of barium chloride / barium nitrate solution shake well
2 cm3 of the unknown solution pour into a test tube 2 cm3 of dilute sulphuric acid + 2 cm3 of iron(II) sulphate solution shake well. Then drop carefully and slowly a few drops of concentrated sulphuric acid along the side of a slanting test tube into the mixture without shaking it.
Confirmatory Test for Fe 2+ , Fe 3+ , Pb 2+ , NH 4+ Ions
Confirmatory Test for Fe 2+ Reagent Observation ConclusionPotassium hexacyanoferrate(II) solution
Pale blue precipitate
Dark blue precipitate
Potassium hexacyanoferrate(III) solution
Dark blue precipitate
Greenish-brown solution
Potassium thiocyanate solution
Pale red colouration
Blood red colouration
Confirmatory Test for Pb2+
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Method Observation Ionic Equation
Using aqueous solution of chloride - 2 cm3 of any solution of Cl- + 2 cm3 of any solution of Pb2+ dilute with 5 cm3 of distilled water heat until no further change occurs allow the content to cool to room temperature using running water from the tap
Using aqueous solution of iodide - 2 cm3 of any solution of I- + 2 cm3 of any solution of Pb2+ dilute with 5 cm3 of distilled water heat until no further change occurs allow the content to cool to room temperature using running water from the tap
When heated –
When cooled –
Confirmatory Test for NH4+
Method Observation
2 cm3 of any solution of NH4+ + 2 cm3 of
NaOH / KOH / Ca(OH)2 heat put a piece of moist red litmus paper at the mouth of the test tube
Reaction with Nessler Reagent 2 cm3 of any solution of NH4
+ + 2 cm3 of Nessler Reagent shake well
Do It Yourself !
Describe chemical tests that can be carried out in the laboratory to differentiate between
(a) lead(II) nitrate solution and aluminium nitrate solution
(b) aluminium nitrate solution and zinc nitrate solution
(c) ammonium chloride solution and potassium chloride solution
(d) iron(II) sulphate solution and iron(III) sulphate solution
(e) sodium chloride and sodium sulphate
REVISION EXERCISE 1
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JOM CHEMISTRY A1
1. Write the formulae of the following ions.
Ions Formula Ions Formula
Sodium ion Chloride ion
Potassium ion Nitrate ion
Zinc ion Sulphate ion
Magnesium ion Carbonate ion
Calcium ion Hydroxide ion
Lead (II) ion
Copper(II) ion
Ammonium ion
REVISION EXERCISE 2
1. Write the formulae of the following ionic compounds.
Ions Chloride, Cl- Nitrate, NO3- Sulphate, SO4
2- Carbonate, CO32-
Sodium, Na+
Potassium, K+
Zinc, Zn2+
Magnesium, Mg2+
Calcium, Ca2+
Lead (II), Pb2+
Copper(II), Cu2+
Ammonium, NH4+
2. Write the formulae of the following salts.
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Sodium nitrate : ………………………… Potassium sulphate : ………………………
Magnesium chloride : ………………………… Copper(II) sulphate :………………………
Calcium chloride : ………………………… Zinc sulphate :………………………
Lead (II) nitrate : ………………………… Calcium carbonate :………………………
Sodium carbonate : ………………………… Potassium chloride :………………………
3. Write the formulae of the following acids/ bases/ alkalis.
Copper(II) oxide :………………………… Magnesium oxide :………………………...
Lead (II) oxide :………………………… Sodium hydroxide :………………………...
Potassium hydroxide :………………………… Ammonium hydroxide: ……………………….
Hydrochloric acid :………………………… Nitric acid :………………………...
Sulfuric acid :………………………… Ethanoic acid :………………………...
REVISION EXERCISE 3
1. Complete the following.
Acid + Base / alkali ………………... + ...……………….
Acid + Reactive metal …………………+ ………………….
Acid + Carbonate metal …………………+ ………………… + ………….………..
2. Complete the following equations.
a) HCl(aq) + PbO(s) ……………….. + ………………….
b) HNO3(aq) + NaOH(aq) ……………….. + ………………….
c) HCl(aq) + NH4OH(aq) ……………….. + ………………….
d) H2SO4(aq) + CuCO3(s) ……………….. + ……………… + ………………
e) HCl(aq) + Na2CO3(s) ……………..… + ……………… + ………………
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JOM CHEMISTRY A1
f) HCl(aq) + Mg(s) ……………….. + ………………….
g) H2SO4(aq) + CuO(s) ……………….. + …….……………
h) HNO3(aq) + Zn(s) ……………….. + ………………….
i) HNO3(aq) + MgO(s) ……………….. + ………………….
j) HNO3(aq) + CuCO3(s) …………..…… + ……………… + ……….………
k) H2SO4(aq) + NaOH(aq) ……………….. + ………………….
l) HNO3(aq) + PbCO3(s) ……………….. + ……………… + …….…………
3. Write the chemical equation of each of the following reactions.
a) Dilute hydrochloric acid reacts with magnesium
…………………………………………………………………………………………b) Dilute sulphuric acid reacts with zinc oxide
…………………………………………………………………………………………c) Dilute nitric acid reacts with copper(II) carbonate
…………………………………………………………………………………………d) Dilute sulphuric acid reacts with potassium hydroxide solution
…………………………………………………………………………………………e) Dilute nitric acid reacts with copper(II) oxide
…………………………………………………………………………………………f) Dilute sulphuric acid reacts with lead(II) carbonate
…………………………………………………………………………………………g) Dilute hydrochloric acid reacts with sodium hydroxide solution
…………………………………………………………………………………………h) Dilute sulphuric acid reacts with zinc
…………………………………………………………………………………………i) Dilute sulphuric acid reacts with ammonia aqueous
…………………………………………………………………………………………
REVISION EXERCISE 41 Write the formula of salts formed from each of the following reaction.
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a) Sulphuric acid + copper(II) carbonate
……………………………………………………………………………………………………b) Nitric acid + potassium hydroxide solution
……………………………………………………………………………………………………c) Hydrochloride acid + ammonium hydroxide solution
……………………………………………………………………………………………………
2 Give example s of salts formed from their corresponding acids.Acid Salt Example
Hydrochloric acid Chloride salt
Sulphuric acid Sulphate salt
Nitric acid Nitrate salt
Carbonic acid Carbonate salt
3 Determine whether each of the following salt is soluble or insoluble in water.Salt Solubility ( , X ) Formulae
1. Magnesium chloride2. Lead(II) sulphate3. Calcium carbonate4. Zinc chloride5. Silver chloride6. Potassium carbonate7. Lead(II) nitrate8. Sodium sulphate9. Ammonium chloride10. Barium sulphate11. Copper(II) nitrate12. Copper(II) sulphate13. Copper(II) carbonate14. Iron(II) nitrate15. Iron(III) chloride16. Sodium carbonate17. Ammonium carbonate18. Silver nitrate19. Tin(II) chloride20. Zinc sulphate
4. Write the chemical equation of each of the following reactions.
a) Hydrochloric acid + copper(II) oxide : …………………………………………………
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b) Nitric acid + lead(II) carbonate :………………………………………………….
c) Sulphuric acid + zinc :………………………………………………….
d) Hydrochloric acid + magnesium oxide :………………………………………………….
e) Nitric acid +calcium carbonate :…………………………………………………..
f) Sulphuric acid + magnesium :…………………………………………………..
5. Name a acid and a metal, metal oxide or metal carbonate that can be used to prepare the following salts.
a) Copper(II) sulphate : …………………………………………………………………………
b) Lead(II) nitrate :………………………………………………………………………….
c) Zinc chloride : …………………………………………………………………………
6. Name two aqueous solutions that can be used to prepare the following salts. Write the chemical equation of each reaction.
a) lead(II) sulphate :……….………………………………………………………………….
b) Silver chloride : ………………………………………………………………………….
c) Zinc carbonate : ………………………………………………………………………….
d) Barium sulphate : ………………………………………………………………………….
7. Write the ionic equation of each of the precipitate reactions below.a) Copper(II) nitrate solution + sodium carbonate solution
…………………………………………………………………………………………………b) Zinc chloride solution + lead(II) nitrate solution
…………………………………………………………………………………………………. c) Dilute sulphuric acid + barium nitrate solution
…………………………………………………………………………………………………. d) Silver nitrate solution + hydrochloride acid
………………………………………………………………………………………………….
Mastery Exercise 8.1Name the salt and state whether each of the following salt is soluble or insoluble in water.
No Formula of Salt Name of Salt Solubility ( , X )
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1 PbCO3
2 NaCl3 CaSO4
4 AgNO3
5 K2CO3
6 AlCl3
7 Na2SO4
8 NH4NO3
9 CuSO4
10 PbCl2
11 ZnCO3
12 Ca(NO3)2
13 Na2CO3
14 AgCl15 PbSO4
16 Pb(NO3)2
17 (NH4)2CO3
18 HgCl2
19 Na2SO4
20 NaNO3
21 MgCO3
22 KCl23 (NH4)2SO4
24 Cu(NO3)2
25 SnCO3
26 CaCl2
27 BaSO4
28 KNO3
29 Ag2CO3
30 MgCl2
31 Ag2SO4
32 Ba(NO3)2
33 FeCO3
34 NH4Cl35 Fe(NO3)3
36 MgSO4
37 BaCO3
38 ZnCl2
39 FeSO4
40 Mg(NO3)2
Mastery Exercise 8.2: Describe the preparation of soluble salts (not Na, K, NH4
+ salt)
Soluble salt Copper(II) sulphate, CuSO4
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JOM CHEMISTRY A1
Name two chemical substances to prepare the salt 1. …………..…………………………..
2. ………………………………………
Chemical equation
Procedure: (Diagram) Description
Mastery Exercise 8.3: Describe the preparation of soluble salts of Na, K and NH4
+
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JOM CHEMISTRY A1
Soluble salt Sodium Chloride, NaCl
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Name two chemical substances to prepare the salt 1. …………..…………………………..
2. ………………………………………
Chemical equation
Procedure: (Diagram) Description
Mastery Exercise 8.4: Describe the preparation of insoluble salts
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Soluble salt Lead(II) iodide, PbI2
Name two chemical substances to prepare the salt 1. …………..…………………………..
2. ………………………………………
Chemical equation
Ionic equation
Procedure: (Diagram) Description
Numerical Problems involving stoichiometric reactions in the precipitation of salts
Question 1:A student prepare copper(II) nitrate, Cu(NO3)2 by reacting copper(II) oxide, CuO with 200 cm3 of 2.0
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JOM CHEMISTRY A1
moldm-3 nitric acid, HNO3. Calculate the mass of copper(II) oxide, CuO needed to react completely with the acid. [Relative atomic mass: Cu, 64 ; O, 16]
Question 2:X cm3 of 0.5 moldm-3 sulphuric acid, H2SO4 is added to 100 cm3 of 1.0 moldm-3 lead(II) nitrate solution to produce lead(II) sulphate, PbSO4.
a. Calculate the value of X.b. Calculate the mass of lead(II) sulphate obtained.
[Relative atomic mass: Pb, 20; O, 16; S, 32]
Question 3:Ammonium phosphate, (NH4)3PO4 is used as a fertiliser. 29.8 g of this salt is prepared by neutralising phosphoric acid, H3PO4 with ammonia gas, NH3. Calculate the volume of ammonia gas, NH3 reacted at room conditions.
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[Ar = H, 1; N, 14; P, 31; O, 16. Molar volume: 24 dm3 mol-1 at room conditions]
Question 4:Silver salts such as silver iodide, AgI are used in photography. A sample of the insoluble salt, AgI is prepared by mixing 50 cm3 of 1.0 mol dm-3 silver nitrate, AgNO3 solution and 50 cm3 of 1.0 mol dm-3 potassium iodide, KI solution. Calculate the mass of silver iodide, AgI produced.[Ar = Ag, 108; I, 127]
Question 4:Acids reacts with calcium carbonate, CaCO3 in limestone to form a salt and carbon dioxide, CO2. A piece of limestone reacted completely with 100 cm3 of 31.5 g dm-3 nitric acid, HNO3. [Ar = H, 1; C, 12; N, 14; O, 16; Ca, 40. Molar volume: 24 dm3 mol-1 at room conditions]
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a. Calculate the mass of salt produced. b. What is the volume of carbon dioxide, CO2 liberated at room conditions?
Prepared by;Kamal Ariffin Bin SaaimSMKDBL
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