What is the concentration in molarity of a solution which is 4.31 %m/v benzene (C₆H₆, MM =78.11 g/mol ) in CCl₄ (MM = 153.81 g/mol)?

Answer 1

Molarity is defined as moles of solute per liter of solution. Since we are dealing with 2 liquids, we take the one present in greater amount as the solvent (CCl4) and the one present in lower amount as the solute (C6H6).

4.31% m/v means 4.31 g C6H6 / 100 ml CCl4 = 43.1 g C6H6 / L

Converting this to moles / L we have...

43.1 g C6H6 x 1 mol/78.11 g = 0.552 moles C6H6 per L of CCl4

Molarity (M) = moles / L = 0.552 moles / 1 L = 0.552 M