35 cm3 of hydrogen was sparked with 12 cm3 of oxygen at 110°C and 760mm Hg to produce steam. What percentage of the total volume of gas left after the reaction is hydrogen?
-
A.
11% -
B.
31% -
C.
35% -
D.
69%
Correct Answer: Option B
Explanation
Reaction for the equation:
(2H_{2} + O_{2} to 2H_{2} O)
(2 vol : 1 vol : 2 vol)
Hence, 2 volumes of Hydrogen is needed for the reaction with Oxygen to produce steam (water).
(therefore 12cm^{3} O_{2} to 2 times 12cm^{3} = 24cm^{3} H_{2})
(text{Excess of Hydrogen} : 35 cm^{3} – 24 cm^{3} = 11 cm^{3})
(text{% Hydrogen left after the reaction} = frac{11}{35} times 100% = frac{220}{7} = 31.48% )
(approxeq 31% )