Chemistry question

Question

Aqueous solutions that contain silver ions are usually treated with chloride ions to recover silver chloride. What is the minimum volume of 0.25 mol/L magnesium chloride need to precipitate all the silver ions in 60. mL of 0.30 mol/L silver nitrate.

Answer 1

Write a balanced equation...

2AgNO₃(aq) + MgCl₂(aq) ==> 2AgCl(s) + Mg(NO₃)₂(aq)

moles AgNO₃ present = 60 ml x 1 L/1000 m x 0.3 mol/L = 0.018 mol

moles MgCl₂ needed = 0.018 mol AgNO₃ x 1 mol MgCl₂/2 mol AgNO₃ = 0.009 moles MgCl₂ needed

volume MgCl₂ needed: (0.25 mol/)(x L) = 0.009 moles

x = 0.036 L = 36 mls needed