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

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

Correct Answer: Option B

Explanation
2H2(g) + O 2(g) → 2H2Og
2V………. IV …………2V

600cm³ … 300cm³ …. 600cm³

The volume of hydrogen left over

= 1000 – 600 = 400cm³