Please fill in the following fields with the data from the run you are checking
ID: 940772 • Letter: P
Question
Please fill in the following fields with the data from the run you are checking about: 1. The mass of the unknown sample : .3998g (should be about 0.3000-0.4000 g) (0.xxxx, 4 significant figures) 2. The mass of the AgCl precipitated:.8934 g (0.xxxx, 4 significant figures) 2. The molar mass of AgCl: g/mol 3. The molar atomic mass of Cl: g/mol First, you convert the mass of AgCl precipitate into the mole of AgCl: mol(AgCl) = g(AgCl)/molar mass (AgCl). mole of AgCl : mol Then, you find the mole of Cl from the mole of AgCl. Hint: What is the molar ratio of Cl to AgCl? mole of Cl: mol Finally, you can calculate the mass of Cl from the mole of Cl and divide the result by the mass of unknown sample to calculate the %Cl. Now give your calculated %Cl below: %Cl:
Explanation / Answer
molar mass of AgCl = 143.3 g /mol
atomic mass of Cl- = 35.5 g/mol
Ag+ + Cl - ----------------------> AgCl
moles of AgCl = mass / molar mass
= 0.8934 / 143.3
= 6.234 x 10^-3
moles of AgCl = moles of Cl = 6.234 x 10^-3
mass of Cl = 6.234 x 10^-3 x 35.5
mass of Cl = 0.2213 g
% Cl = (mass of Cl / sample mass) x 100
= (0.2213 / 0.3998) x 100
= 55.36 %