Answer : The molarity of the AgNO₃ solution is 0.408 M
Answer :
The balanced chemical equation for the reaction between KCl and AgNO₃ is given below.

Step 1 : Find moles of KCl.
The mass of KCl is given as 785 mg. Let's convert this to grams.

The molar mass of KCl is 74.55 g/mol
The moles of KCl can be calculated as,


We have 0.0105 mol KCl
Step 2 : Find moles of AgNO₃.
The mole ratio of KCl and AgNO₃ is 1 : 1.
The moles of AgNO₃ can be calculated using this mole ratio.

We have 0.0105 mol AgNO₃.
Step 3 : Use molarity formula.
The molarity of AgNO₃ can be calculated as,

The volume of AgNO₃ solution is 25.8 mL which is 0.0258 L.

The molarity of the AgNO₃ solution is 0.408 M.