Calculate the molarity of a solution prepared by dissolving 0.20 mol of KNO3 into enough water to make 250 mL of solution. M

0.8M

Explanation:

Given parameters:

Number of moles of KNO₃  = 0.2mol

Volume of KNO₃ = 250mL

Unknown:

Molarity of the solution  = ?

Solution:

The molarity of a solution is the number of moles in a given volume of a solution;

         Molarity  =

 We need to convert the given volume to L;

                1000mL  = 1L

        250mL will give  250 x 10⁻³L = 0.25L

So;

        Molarity  =   = 0.8M

the answer to your question is c

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.