On repeated sparking, `10 mL` of a mixture of carbon monoxide and nitrogen required `7 mL` of oxygen for combustion. What was the volume of nitrogen? (All volumes are measured under identical conditions).

Options

A. `7//2 mL`
B. `4 mL`
C. `7 mL`
D. `17//2 mL`

Answer

B

Explanation

`CO = x mL, N_(2) = (10 - x) mL`
`CO_(2) + (1)/(2) O_(2) rarr CO_(2)`,
`N_(2) + O_(2) rarr 2NO`
`O_(2)` required `= (x)/(2) mL`, `O_(2)` required `= (10 - x) mL`
`(x)/(2) + (10 - x) = 7`, `x = 6 mL`
`N_(2) = 10 - 6 = 4mL`