@When hydrogen burns in air it combines with:
Oxygen
Nitrogen
Inert gases

@When hydrogen burns in the air it produces:
Steam
A salt
More hydrogen

@Compared to air, the density of hydrogen gas is:
Less than air
About the same as air
Greater than air

@Pure hydrogen burns with a flame coloured:
Blue
Orange
Red

@If a lighted splint is put into a test tube containing hydrogen then it will:
Make a popping sound
Burn more brightly
Make the splint go out

@To make hydrogen in the lab, what two substances are usually used?
Hydrochloric acid and zinc
Sulphuric acid and copper
Sodium hydroxide and magnesium

@The diagram shows a piece of apparatus designed to collect and measure hydrogen gas. The tube initially contains air. The apparatus is unsuitable because:
#invert1
Hydrogen is colourless and so its volume will not be seen on the scale
The test tube is the wrong way up
Hydrogen would combine with the air

@Which one of the following is NOT a physical property of hydrogen?
It is acidic
It is almost insoluble in water
It is odourless

@Which of the following statements is correct?
Hydrogen molecules travel much faster than air molecules
Hydrogen molecules and air molecules travel at about the same speed
Hydrogen molecules only travel very slowly

@The diagram shows an experiment set up to test the diffusion of hydrogen. If the apparatus is left for some time:
#diff2
The level in tube x goes down and the level in tube y up
The two levels in x and y stay the same
The level in tube y goes down and the level in x goes up

@This apparatus is used to show the diffusion of hydrogen. The pot is porus so that:
#diff2
Gas molecules can pass through it
Hydrogen can't get to the air
Air can't escape

@Hydrogen gas enters at the left, and is burning on the right. What can be seen on the cold surface?
#burn
Water droplets
Soot
Yellowish deposit

@Hydrogen gas is passed through the apparatus shown, and burnt as it emerges. The purpose of the anhydrous calcium chloride is:
#burn
To dry the hydrogen
To add oxygen to the hydrogen
To produce an even flow of hydrogen gas

@Hydrogen gas is passed through this apparatus and burnt as it emerges. Water is formed on the cold surface because:
#burn
The hydrogen combines with oxygen in the air
There is water vapour in the air
The anhydrous calcium chloride is moist