Question

Calculate the molarity of each of the following solutions.

Part A

0.43 mol of LiNO3 in 6.44 L of solution

Express your answer using two significant figures.

molarity =

M  

Part B

11.45 mg KI in 114.8 mL of solution

Express your answer using four significant figures.

molarity =

  M  

Answer 1

A)

molarity = moles / volume (L)

             = 0.43 / 6.44

            = 0.067 M -------------------->answer

B)

11.45 mg KI in 114.8 mL of solution

mass of KI = 11.45 mg = 11.45 x 10^-3 g

molar mass of KI = 166.0 g / mol

moles = mass / molar mass

         = 11.45 x 10^-3 / 166

        = 6.90 x 10^-5

volume = 114.8 mL = 0.1148 L

molarity = moles / volume

             = 6.90 x 10^-5 / 0.1148

            = 6.008 x 10^-4 M -----------------> answer