Answer to Question #72650 in General Chemistry for Chloe Lozano

Question

The balanced equation for this reaction is _______.

A. Na2S2O3 + Cl2 + H2O → NaHSO4 + HCl
B. Na2S2O3 + 4Cl2 + 5H2O → 2NaHSO4 + 8HCl
C. 2Na2S2O3 + 4Cl2 + 5H2O → 2NaHSO4 + 8HCl
D. Na2S2O3 + 2Cl2 + 8H2O → 2NaHSO4 + 4HCl
E. None of the Above
use the following: Chlorine is used to bleach cloth. Excess Chlorine is destroyed by its reaction with Sodium Thiosulfate (Na2S2O3) according to the unbalanced equation Na2S2O3 + Cl2 + H2O → NaHSO4 + HCl.

Answer 1

A balanced equation must have equal numbers of each type of atom on both sides of the arrow. The coefficient times the subscript gives the total number of atoms. An equation is balanced by changing coefficients in a somewhat trial-and-error fashion. To get S and Na balanced, we put 2 in front of NaHSO4 , then the total number of O atoms is 8, to balance it we put 5 in front of H2O. And, lastly, to get 10 H on the both sides, we change the coefficient before HCl and balance the Cl afterwards:
Na2S2O3 + 4 Cl2 + 5 H2O = 2 NaHSO4 + 8 HCl .
This balanced equation matches the option B.
Answer: B.