NEET Solved Paper 2014 Question 3
Question: Equal masses of $ H _2,O _2 $ , and methane have been taken in a container of volume V at temperature $ 27{}^\circ C $ in identical conditions. The ratio of the volumes of gases $ H _2:O _2:CH _4 $ would be [AIPMT 2014]
Options:
A) 8 : 16 : 1
B) 16 : 8 : 1
C) 16 : 1: 2
D) 8 : 1 : 2
Show Answer
Answer:
Correct Answer: C
Solution:
According to Avogadro’s hypothesis, Volume of a gas (V) $ \propto $ number of moles (n) Therefore, the ratio of the volumes of gases can be determined in terms of their moles. The ratio of volumes of $ H _2 $ : $ O _2 $ : methane $ (CH _4) $ is given by $ {V _{H _2:}}{V _{O _2}}:{V _{CH _4}}={n _{H _2}}:{n _{O _2}}:{n _{CH _4}} $
Þ $ {V _{H _2}}:{V _{O _2}}:{V _{CH _4}}=\frac{{m _{H _2}}}{{M _{H _2}}}:\frac{{m _{O _2}}}{{M _{O _2}}}:\frac{{m _{CH _4}}}{{M _{CH _4}}} $
But $ {m _{H _2}}={m _{O _2}}={m _{CH _4}}=m[ \because ,n=\frac{mass}{molar,mass} ] $
Thus, $ {V _{H _2}}:{V _{O _2}}:{V _{CH _4}}=\frac{m}{2}:\frac{m}{32}:\frac{m}{16}=16:1:2 $
