Answer to Question #319942 in General Chemistry for jjoel

Question

An aqueous solution of Borax (Na2B4O7) is sometimes used to fireproof wood. 

What is the molarity of 45.0 L of solution that contains 6.78 kg of Na2B4O7?

Answer 1

C_M = n / V

n = m / M

M (Na₂B₄O₇) = 201.2 g/mol

n = 6780 / 201.2 = 33.7 mol

C_M (Na₂B₄O₇) = 33.7 / 45 = 0.75 M