A 150 cm³ solution containing Br^- was treated with excess AgNO₃ in order to find the Br^- concentration in the solution. 0.873 g of AgBr was precipitated out. What was the concentration (in mol dm^-3) of Br^- in the unknown solution?

Question

Quizplus · Accepted Answer

The molar mass of AgBr is approximately 187.77 g/mol. The moles of AgBr precipitated are 0.873 g / 187.77 g/mol = 0.00465 mol. Since the reaction between Br⁻ and Ag⁺ is 1:1, the moles of Br⁻ are also 0.00465 mol. The concentration of Br⁻ in the solution is 0.00465 mol / 0.150 dm³ = 0.031 mol/dm³.

A 150 Cm3 Solution Containing Br- Was Treated with Excess

A 150 Cm³ Solution Containing Br^- Was Treated with Excess