Question

How many moles of Na₂S₂O₃ are needed to react with 0.04 moles of C1₂?

A. 0.10 mol Na₂S₂O₃

B. 0.20 mol Na₂S₂O₃

C. 0.30 mol Na2S2O3

D. 0.40 mol Na2S2O3

E. 0.50 mol Na2S2O3

Answer 1

First of all, there is no correct answer in the multiple choices given.

The correct answer is 0.01 moles of Na₂S₂O₃

Because the balanced equation for the implied reaction is;

Na₂S₂O₃ + 4Cl₂ + 5H₂O $\to$ 2NaHSO₄ + 8HCl

Thus, the mole ratio of Na₂S₂O₃:Cl is 1:4

Moles of Na₂S₂O₃ $=\dfrac{1}{4}x0.04 = 0.01moles$ of Na₂S₂O₃