Question

what is the molarity of a concentrated hbr solution if the solution is 27.7% hbr by mass and has a density of 1.24 g/ml

Answer 1

Answer:
M = No.of moles of solute / Volume of solution in litres
HBr: H = 1 x 1 = 1 Br = 1 x 80
Molar mass : 81 g / mol
a. n = 27.7% / 100 =0.277 g / (81 g / mol) = 0.0034 mol

density = 1.24 g/ml ; D= m / v

b. 65.32 ml x 1 L / 1000 mL = 0.065 L


c. M= n / V
= 0.0034 mol / 0.065 L
M= 0.052 mol / L

The molarity of the concentrated HBr solution is 0.052 mol/L