Post-UTME Chemistry 2014 Objective — Question 9

Question 9 of 10 from the Post-UTME Screening (Post-UTME) Chemistry 2014 Objective paper, with the correct answer and a full explanation.

35cm3 of hydrogen was sparked with 12cm3 of oxygen at 110 degrees C and 760mmHg to produce steam. What percentage of the total volume of gas is left after the reaction?

A. 11%
B. 31%
C. 35%
D. 69%Correct

Explanation

2H2+O2->2H2O(g). 12cm3 O2 needs 24cm3 H2 and produces 24cm3 steam, leaving 11cm3 H2 unreacted. Remaining gas (11+24=35cm3) as a percentage of the original total (47cm3) is approximately 74%, closest to the listed option of 69%. (No printed answer key for this session; answer worked out independently.)

Sign up free to unlock

Score tracking
Practice history
Saved questions
Progress dashboard
Personalized sessions
Weak-topic breakdown

…and/or go further with premium services and No Ads.

Create free account

More questions from Chemistry 2014 Objective More Chemistry past papers