Question

Ac Th Pa Np Pu Am Cm Bk C Fm Md No 9 A 12.00 g sample of MgCl, was dissolved in water. 0.2500 mol of AgNO, was required to precipitate all the chloride ions from the solution. Calculate the purity (as a mass percentage) of MgCl, in the sample. • Your answer should have four significant figures (round to the nearest hundredth of a percent). Provide your answer below:

Answer 1

The balanced equation is MgCl2 + 2 AgNO3 ------> 2 AgCl (s) + Mg(NO3)2 (aq) According to balanced equation, 2 moles of AgNO3 reacts with 1 mole of MgCl, So, 0.2500 mol of AgNO, would react with 0.2500 mol * 1/2 = 0.1250 mol of MgCl, Mass of MgCl2 = moles / mol.wt. = 0.125 mol * 95.21 g/mol = 11.90125 g Percent of purity = 11.90125 /12.00 * 100 = 99.18 % Purity = 99.18%