Answer:
% = 5.69%
Explanation:
To do this, we need to write the equations taking place here. First, this is a REDOX reaction where the hypoclorite and thiosulfate solution reacts. The balanced equations are:
ClO⁻ + 2I⁻ + 2H⁺ -------> Cl⁻ + I₂ + H₂O
I₂ + 2S₂O₃²⁻ -----------> 2I⁻ + S₄O₆²⁻
We already have the required volume and concentration of the thiosulfate solution, so we can calculate the moles of thiosulfate. With this moles, we can calculate the moles of hypochlorite, then the mass and finally the %.
The moles of thiosulfate would be:
moles S₂O₃²⁻ = V * M
moles S₂O₃²⁻ = 0.01324 * 0.0732 = 9.69x10⁻⁴ moles
Now according to the above reactions, we can see that
moles I₂ = moles ClO⁻
and
moles I₂ / moles S₂O₃²⁻ = 1/2
Therefore, let's calculate the moles of ClO⁻:
moles ClO⁻ = 9.69x10⁻⁴ / 2 = 4.845x10⁻⁴ moles
Now, we can calculate the mass of these moles, using the molar mass of sodium hypochlorite which is 74.44 g/mol:
m = 74.44 * 4.845x10⁻⁴
m = 0.036 g
Finally the % of this, in the bleach sample would be:
% = 0.036 / 0.634 * 100
<h2>
% = 5.69%</h2>
