Question

The volume of oxygen required for complete combustion of 20 ml of ethene is

• A. $70L$
• B. $50L$
• C. $60L$
• D. $40L$

Answer 1

Answer: (C)

$60L$

We have

$C_2{H}_4+3O_2\to 2C{O}_2+2H_{2}O$

At STP we have

volume of 1 mole of gas = 22400 ml

so, moles of ethene in 20 ml of volume = $\frac{1}{22400}\ast 20=0.00089moles$

for, 1 mole of ethene we require 3 mole of oxygen

so, for 0.00089 mole of ethene we require oxygen = $0.00089\times 3=0.00267mole$

hence, volume of oxygen require = $22400\times 0.00267=60ml$