Question

How many liters of O2 at STP will react with 8.7 grams of C2H4 to form CO2 and H2O?

C2H4 + 3 O2 -------> 2 CO2 + 2 H2O
Pls help
answers can be
21
22
2.3

Answer 1

The volume of O₂ : 21 L

Further explanation

Given

8.7 grams of C₂H₄

Required

Volume O₂

Solution

Reaction

C₂H₄ + 3 O₂ ⇒ 2 CO₂ + 2 H₂O

mol C₂H₄(MW= 28 g/mol) :

= mass : MW

= 8.7 g : 28 g/mol

= 0.311

From the equation, mol O₂ :

= 3/1 x mol C₂H₄

= 3/1 x 0.311

= 0.933

At STP, 1 mol gas=22.4 L, so for 0.933 mol :

= 0.933 x 22.4 L

= 20.899 L ≈ 21 L