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Mol 12 Measure the molar volume of hydrogen with an aluminium Cola can
Attention: Hydrochloric acid is corrosive
The molar volume is the volume of 1 mol of a gas  (i.e. hydrogen) at 0°C and 1013 hPa: 22.4 liters.
1 molar volume at room temperature is about 24 liter, that means 1 millimol = 24 ml.
Aluminium reacts with hydrochloric acid: It releases a gas and dissolves.
According to the equation:  Al(s) + 3 HCl(aq) -----> 3/2 H2(g) +  AlCl3(aq)
0.1mmol (2.7 mg) aluminium releases  3/2 x 2.4 ml = 3.6 ml hydrogen.

What you need: Cola can, sand paper, scissors, millimeter paper, Scale with 200-mg-weigt, 5-ml-syringe, burner, film canister, hydrochloric acid 2-molar, 1 drop of ink.
Experiment left: Carefully clean a piece of Cola can by sand paper
* cut  a piece of shiny Cola metal and balance it by a 0.2 g-weight,
* cut a smaller piece of 2 x 5 mm (= 2.7 mg aluminium).
Photo 2: Use a heated scissors to melt a small slit into the the vial´s bottom. ( To insert the Al sample).
* Suck 6 ml of acid (dyed with a drop of ink) from the film canister into the syringe.
* Insert the Al sample into the syringe. Dip it into the canister, read the volume at the surface: 5,5 ml.
Observation photo 3: The aluminium sample has already released 5.5 - 1.8 ml of a gas.
Observation photo right: The aluminium sample dissolved releasing 5.5 - 1,4 ml of a gas.
Explanation: While the aluminium sample dissolved by chemical reaction with hydrochloric acid it released a volume of hydrogen equivalent to its mass.

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