Consider the following balanced chemical equation, kcl(aq) agno3(aq) → agcl(s) kno3(aq)when a sample of impure potassium chloride (0.900 g) was dissolved in water, and treated with excess silver nitrate (agno3), 1.26 g of silver chloride (agcl) was precipitated. calculate the percentage kcl in the original sample.

In the original sample there's 72.78% KCl

Explanation:

KCl(aq) + AgNO₃(aq) → AgCl(s) + KNO₃(aq)

To solve this problem we need to calculate the mass of pure potasssium chloride. To do that we calculate the moles of KCl that reacted into AgCl:

1.26 g AgCl *

Now with the molecular weight of KCl, we can calculate the mass of KCl that reacted:

8.792 * 10⁻³ mol KCl * 74.55 g/mol = 0.655 g KCl

Finally we divide the mass of pure KCl by the mass of the sample, to calculate the percentage KCl:

0.655 / 0.900 * 100% = 72.78%