7/30/2019 exp 4.1 for group 1

1/8

Experiment 4.1

To Investigate the Chemical Properties of:

Lithium Sodium Potassium

http://www.seilnacht.com/film/kalium.mpghttp://www.seilnacht.com/film/natrium.mpghttp://www.seilnacht.com/film/lithium.mpg

7/30/2019 exp 4.1 for group 1

2/8

How does the reactivity of group 1 element change when

they react with water and oxygen gas, O2?

A. The reaction of alkali metals with water.

Hypothesis:

When going down Group 1, alkali metals become more reactive in their reactions

with water.

B. The reaction of alkali metals with oxygen gas, O2

Hypothesis:

When going down Group 1, alkali metals become more reactive in their reactions

with oxygen gas, O2

7/30/2019 exp 4.1 for group 1

3/8

A. The reaction of alkali metals with water.

Procedure:

A. Cut a small pieces of lithium using a knife and forceps.B. Dry the oil on the surface of the lithium with filter paper.

C. Place the lithium slowly onto the water surface in a trough.

D. When the reaction stops, test the solution produced with red litmus paper.

E. Teacher will demonstrate step A to Dusing sodium.

F. Record your observation.

7/30/2019 exp 4.1 for group 1

4/8

B. The reaction of alkali metals with oxygen gas, O2

Procedure:

A. Cut a small piece of lithium using a knife and forceps.B. Dry the oil on the surface of the lithium with filter paper.

C. Put the lithium in a gas jar spoon

D. Heat the lithium strongly until it burns.

E. Transfer the gas jar into a gas jar filled with oxygen gas.

F. Observe what happen.

G. When the reaction stops, pour 10cm3 of water into the gas jar.Shake the gas jar. Test the solution formed with red litmus paper.

A. Teacher demonstration on sodium on step A G.

B. Record your observation.

7/30/2019 exp 4.1 for group 1

5/8

Data and observation:

Section lithium sodium Potassium

A Lithium melts and

moves slowly at

random on the

surface of water with

plenty of fizz. Acolourless solution

that turns red litmus

paper blue is formed

Sodium melts and move

rapidly at random on the

surface of water with a

hissing sound. A

colourless solution thatturns red litmus paper

blue is formed

Potassium melts, moves

very fast at random on

the surface of water and

ignites with a lilac flame,

with pop and hissingsound. A colourless

solution that turns red

limus paper blue is

formed.

7/30/2019 exp 4.1 for group 1

6/8

B Lithium burns slowly

with a red flame.

White fumes are

produced which

become a white solid

when cooled to room

temperature.

The white solid

formed dissolves in

water to form a

colourless solution

that turns red litmus

paper blue.

Sodium burns rapidly

with bright yellow flame.

White fumes are

produced which become

a white solid when

cooled to room

temperature.

The white solid formed

dissolves in water to

form a colourless

solution that turns red

litmus paper blue.

Potassium burns very

rapidly and violently

with a lilac flame. White

fumes are produced

which become a white

solid when cooled to

room temperature.

The white solid formed

dissolves in water to

form a colourless

solution that turns red

litmus paper blue.

7/30/2019 exp 4.1 for group 1

7/8

Questions:

What happen when lithium, sodium andpotassium is replace with Rubidium, Cesium

and Francium in both reaction?

ANSWER

http://localhost/var/www/apps/conversion/tmp/My%20Videos/RealPlayer%20Downloads/Brainiac%20Alkali%20Metals.flvhttp://localhost/var/www/apps/conversion/tmp/My%20Videos/RealPlayer%20Downloads/Brainiac%20Alkali%20Metals.flv

7/30/2019 exp 4.1 for group 1

8/8