PRACTICUM 7 (Principles of Chemistry)
“GAS LAW: THE QUANTITATIVE DISPLACEMENT OF
HYDROGEN BY METALS”
By:
Edi (ISI)
Farras Reyhan Hiyatullah (2014990004)
Nabila Soraya R(2013320001)
Rizky Akbar (ISI)
1
Abstract
In this experiment, we will do the reaction between acid and solid metals and then
measure the volume of hydrogen gas product. Based on the chemical equation, the amount of
solid metals reacted and hydrogen produced, we also determine the relative atomic mass of
metals.
Objectives
1. To determine the molar vomule of hydrogen gas produced by redox reaction.
2. To determine the relative atomic mass of metals reacted.
2
Materials
Chemicals Equipments
Zn(s) Glass apparatus
Mg(s)
Al(s)
Aqua dm
Experimental Procedure
Experimental Method
1. Add 0.2gr to the rounded bottom flask 3 and then set up the apparatus as shown below
2. Fill the rounded bottom flask 2 with water
3. Disassemble the connection at A and open the stopcock #1
4. Move the water from flask 2 to beaker 1. Immediately close the stopcock #1 when the
water starts to enter the beaker. Make sure that the pipe B is complety filled with water.
Dispose the water inside the beaker 1. Then reconnect the rubber pipe A.
5. Sometime open the stopcock #2 and then close again to set the pressure inside and
outside the apparatus same
6. Open the stopcock #1. See whether the water flows to the beaker 1. If yes, it means that
there is leakage at some connections in the apparatus. Before starting the experiment, fix
the set up until no leakage
7. After the apparatus is ready to use, pour 20ml HCl 6M into the rounded bottom flask 3
through the funnel. Open the stopcock #2 slowly and allow HCl to flow into the flask 3
drop by drop
8. Immediately close the stopcock #2 if the reaction proceeds to fast. If the reaction
completes, the metal solid will be disappeared and the formation of gas will be stopped.
9. Fill the funnel with water and then fill gradually into the rounded bottom flask 3 to lower
the temperature. Make sure that the water is always inside the funnel. Repeat this step
with the same amount of water
3
10. Note: the excess of water will flow into beaker 1
11. Wait until the reaction finished and has cooled slightly (about 5 minutes)
12. Measure the temperature of the water height in the beaker same with the height in the
rounded bottom flask 2
13. Raise up and down the beaker until water height in the beaker same with the height in the
rounded bottom flask 2
14. Measure the volume of the water inside the beaker and the volume of water inside the
rounded bottom flask 3
15. Measure the atmospheric pressure during the experiment
16. Do the same thing with the other metals.
Data analysis
1. V
2. C
3. Mg(s) + 2HCl(aq) → MgCl2(aq) +H2(g)
Zn(s) + 2HCl(aq) → ZnCl2(aq) +H2(g)
2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g)
4. Mole ratio of Mg(s) + 2HCl(aq) → MgCl2(aq) +H2(g) is:
1 :2 → :1 :1
So, for n Magnesium, it required 2n moles of acid. Also will produced 1n mole of
magnesium chloride and 1n mole of hydrogen.
Mole ratio of Zn(s) + 2HCl(aq) → ZnCl2(aq) +H2(g) is:
1 :2 → :1 :1
So, for n zinc, it required 2n moles of acid. Also will produced 1n mole of zinc chloride
and 1n of hydrogen.
Mole ratio of 2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g) is:
2: 6 → :2 :3
4
So, for n of alumunium, it required 3n moles of acid. Also will produced 1n mole
3
alumunium chloride and n mole of hydrogen.
2
5. G
6. H
7. G
