Question

2 mole of each of O2 and H2 are in seperate containers each of volume Vo and at 150C and 1 atmosphere. the 2 are made to react in a third container to form water vapour until H2 is exhausted. when temperature of the mixture in the third container was restored top 150C its pressure becomes 1 atmosphere the volume of third container must be
1. Vo
2. 5Vo/2
3. 3Vo/2
4. 2Vo

Answer 1

look at the equation \(O_2+2H_2\rightarrow 2H_2O\)

if you had \(V_{\circ}\) of \(H_2\), then the volume of \(H_2O\) you can make is only \(V_{\circ}\) (note their coefficients).

Are you also supposed to take the volume of \(O_2\) into account? if so you need to add \(\dfrac{1}{2}V_{\circ}\) to the volume of \(H_2O\) vapour.