Jim’s Laboratory Notes for Creating Hydrogen Gas. Home Chemistry, May 2000 Other experiments:

- March 2001 Microbiology "Do antigermicides work?"(with video)
Background

Hydrogen is a colourless, odourless, tasteless, flammable and non-toxic gas at atmospheric temperatures and pressures. It is the lightest gas known, being only some seven one hundredths as heavy as air. Hydrogen is present in the atmosphere, occurring in concentrations of only about 0.01 per cent by volume at lower altitudes. Its’ international symbol is (H2), its’ molecular weight is 2.016

Hydrogen burns in air with a pale blue, almost invisible flame. Many will be aware of the airship disaster when the Hindenburg caught fire in 1937 (see photo). Fewer will be aware that the biggest user of hydrogen today is NASA who use liquid hydrogen as fuel for space craft. Hydrogen produces no pollution and many scientists and engineers are working to create cheap and plentiful supplies of hydrogen for energy.

Objective

My objective is to prove that hydrogen is flammable and that it is lighter than air. I hypothesise that I can collect hydrogen in a balloon as it will rise out of the bottle. I should also be able to light the gas at the bottles’ opening.

Experiment

Safety Note
The first step is to ensure that you have protective gear including glasses and a laboratory coat. Gloves can also be worn. Should be done under adult supervision.

* caustic soda is highly corrosive and can burn skin

The requirements for this experiment include:

• Test tube or dry glass bottle
• Caustic soda * (sodium hydroxide- H SO-4 I think!)
• Aluminium foil (Al)
• Funnel
• Small spoon
• Hot water (H-2-O)
•Container for water
• Balloon

Experiment method using bottle

:
1. Cut aluminium foil into 15 small bits (stamp size)
2. Place foil in bottle
3. Add 3 teaspoon of caustic soda
4. Add about 500ml of hot water to bottle
5. Rotate bottle & cover hole immediately with balloon to collect gas which will form. When some gas has formed, remove and tie balloon
6. When removing balloon cover hole with foil, wait 2 minutes and then poke hole in foil just as a lighted match is placed over top.

Observations:

When I put the water in with the caustic soda and aluminium they reacted and started to make hydrogen gas. When I put the balloon over the bottle because the gas is so light, it started to fill the balloon. I hypothesise that the aluminium was oxidised (eaten away) by the caustic soda and the water (H-2-O) then reacted with it to create hydrogen.

Then when I put the aluminium over the hole, and put a small hole through it, the hydrogen came out. Because it is flammable a flame started when I lit a match over it. In one experiment, a small explosion occurred.

Step 2 Step3 Step4