Question

How many grams of magnesium bromide, MgBr2, must be dissolved to prepare 400. mL of a 0.183 M aqueous solution of the salt?

Answer 1

Answer: 13.47g of MgBr2

Step-by-step explanation:

MM of MgBr2 = 24 + (2 x 80) = 24 + 160 = 184g/mol

Mass conc. Of MgBr2 = 0.183 x184 = 33.672g

33.672g of MgBr2 dissolves in 1000mL

Therefore Xg of MgBr2 will dissolve in 400mL

Xg of MgBr2 = ( 33.672 x 400)/1000

Xg of MgBr2 = 13.47g