Gas volumes

Question 1

Measuring gas with a burette and cylinder.

Answer 1

• If an upturned burette on measuring cylinder is used it must be filled with water before it is turned upside down. The volume is read off the scale on the side.
• The scale on the burette goes the opposite way to that on a measuring cylinder.

Question 2

Gas syringe

Answer 2

If a balance used, a loose plug of cotton wool in the neck of the flask prevents a spray. The volume of gas produced can be calculated from the mass of gas produced.

Question 3

1 mole of gas

Answer 3

24 dm³

Question 4

volume of gas Eq.

Answer 4

volume of gas = number of moles x 24

Question 5

Number of moles Eq.

Answer 5

number of moles = volume/24

Question 6

What is a limiting reactant?

Answer 6

The reactant that is used up first is the limiting reactant.

Question 7

What happens when a limiting reactant is used?

Answer 7

When the limiting reactant is all used up there are no more particles of that substance to collide with the other reactant, so the amount of product formed is directly proportional to the amount of limiting reactant.