What volume of hydrogen would be left over when 300cm3 of oxygen and 1000cm of hydrogen are exploded in a sealed tube? [2H2(g) + O2(g) → 2H2 Og]

A. 200 cm³
B. 400 cm³
C. 600cm³
D. 700cm³

Correct Answer: Option B

B. 400 cm³

Explanation

2H2(g) + O2(g) → 2H2Og
2V            IV          2V
600cm³ 300cm³ 600cm³
The volume of hydrogen left over
= 1000 – 600 = 400cm³?