(a) (i) What volume of oxygen is required to burn completely 90dm3 of butane under similar conditions of temperature and pressure?
(ii) the vapour density of a gas is 8. What would be the volume occupied by 24.0 g of the gas at STP?
(iii) A vessel contains X number of molecules of hydrogen gas at a certain temperature and pressure. How many molecules of nitrogen gas would be present in the same vessel under the same conditions of temperature and pressure?
(b) O2 is evolved by heating KClO3 using MnO2 as a catalyst.
(i) Calculate the mass of KClO3 required to produce 6.72 litres of O2 at STP.
[atomic masses of K=39,Cl=35.5,O=16]
(ii) Calculate the number of moles of oxygen present in the above volume and also the number of molecules.
(iii) Calculate the volume occupied by 0.01 mole of Co2 at STP.