Please help solve this Chem problem!?

Question

A solid mixture containing only sodium chloride and sodium nitrate has a mass of 4.000g. When this sample is dissolved in water and excess silver nitrate is added, 4.590g of solid silver chloride is formed. Calculate the percent mass of sodium chloride in the original 4.000g mixture.

Answer 1

The AgCl has come from the reaction of NaCl with AgNO3 since NaNO3 does not react with AgNO3. ( at least that won't give u the ppt of AgCl)

Now molecular mass of AgNO3 = 107.88+14+48 = 169.88
molecular mass of AgCl = 107.88+35.5= 143.38
molecular mass of NaCl = 23+35.5 = 58.5

AgNO3 + NaCl = NaNO3 + AgCl

So 1 mol of AgCl will be formed from 1 mol of NaCl
or, 143.38 g AgCl will be formed from 58.5 g of NaCl
or, 4.590 g AgCl will be formed from (58.5*4.590)/143.38 g of NaCl

Hence the wt of Nacl in the sample = (58.5*4.590)/143.38 =1.8728g

Hence the % mass of NaCl = (1.8728/4)*100= 46.8188% (ans)

Answer 2

You can calculate the number of moles of silver chloride, and thus the number of moles of chloride ion. This will equal the number of moles of sodium chloride, from which its mass can be calculated. The remaining part of the calculation is trivial.