An acid will release hydrogen gas when reacted with a metal
Apparatus and chemicals
In this reaction it is very obvious that a gas is produced – you can see fizzing in the boiling tube.
The magnesium also disappears, it is being chemically changed and forming a soluble product.
You may have also noticed that the boiling tube becomes warm, this is evidence that heat is given off during the reaction.
When you collected the gas you should have noticed that it rises to the top of the test-tube and also that the water in the basin has no effect on the gas.
This is because hydrogen is less dense than air and insoluble in water.
You will also have heard a squeaky pop when the lit splint is placed into the test-tube.
This is actually a mini explosion!
The hydrogen is reacting with the oxygen in the air and making water – you may have seen little droplets of water on the side of the test-tube after the reaction.