gneet

Question
Q149) How many litre of oxygen at STP is required to burn 60 g C_{2}H_{6}?

SOLUTION

Molar mass of C_{2}H_{6} = 24+6 = 30g

60g of C_{2}H_{6}= 2 moles

Burning of C_{2}H_{6} equation is

2C_{2}H_{6} + 7O_{2} → 4CO_{2} + 6H_{2}O

Thus 2 moles of C_{2}H_{6} required 7 moles of O_{2}

Now volume of 1 mole of gas at STP = 22.4 L

Volume of 7 moles of O_{2}= 22.4 × 7 L

Answer: (c)