Question

A chemist adds 0.86L of a 9.20/gdL sodium carbonate Na2CO3 solution to a flask.

Calculate the mass in grams of sodium carbonate the chemist has added to the flask. Round your answer to 2 significant digits.

Answer 1

volume = 0.86 L

concentration = 9.20 g / dL

                       = 92 g/L / 106 g/mol

                       = 0.868 M

molarity = moles / volume

0.868 = moles / 0.86

moles = 0.746

molar mass of Na2CO3 = 106 g/mol

mass = moles x molar mass

         = 0.746 x 106

          = 79.12 g

mass of Na2CO3 = 79 g