Avogadro's law and gas volume calculations

Question 1

in the early 19th Century, scientists had discovered that

Answer 1

the volumes of gases that react are in a simple whole-number ratio, provided that the volumes are measured under the same conditions of temperature and pressure

Question 2

when hydrogen reacts with oxygen, the H:O ratio is

Answer 2

2:1

Question 3

the ratio of hydrogen:nitrogen:ammonia is

Answer 3

3:1:2

Question 4

Avogadro’s Law states that

Answer 4

‘equal volumes of gases under the same conditions of temperature and pressure contain the same numbers of molecules’

Question 5

simply put, Avogadro’s law states that:

Answer 5

one mole of any gas occupies exactly the same volume

Question 6

hydrogen and chlorine react to form hydrogen chloride . 100cm3 of each reactant is used, so how much HCL is produced?

Answer 6

ratio is 1:1:2 (H2 + Cl2 → 2HCl) so 200cm3 of HCl is formed

Question 7

50cm3 of nitrogen monoxide and 25cm3 of oxygen react to form nitrogen dioxide.
2NO + O2 → 2NO2
volume of NO2 produced:

Answer 7

50cm3, because the ratio is 2:1:2, so as much NO2 is formed as NO is used

Question 8

200cm3 of sulfur dioxide reacts with 200cm3 of oxygen, what is the volume of sulfur trioxide formed?
2SO2 + O2 → 2SO3

Answer 8

here the solumes do not match the ration 2:1:2, so you must see that all the sulfur dioxide reacts, but with only half the oxygen , so the answer is 200cm3, but with an extra 100cm3 of unreacted oxygen left over