one gram of a mixture of potassium and sodium chloride on treatment with excess of silver nitrate gave 2g of AgCl . what was the composition of the two salts in the original mixture.
Dear student!
Here, given that, mass of NaCl + mass of KCl = 1.000 g
Let, x = grams of NaCl in original mixture so, (1-x) = grams of KCl in original mixture
Therefore:
(x) + (1-x) = 1.000 g
Now, moles of NaCl = given mass/molar mass = x/ 58.5 moles
Similarly moles of KCl = (1-x)/ 74.5 moles
Since, KCl and NaCl are in 1:1 ratio, so the
Mass of AgCl produced by given mole of NaCl = (x/ 58.5 ) x 143.5 = 2.45 x gm
so, mass of AgCl produced by given moles of KCl = [(1-x)/ 74.5] x 143.4 = 1.92 (1-x) gm
So, the total mass of AgCl produced will be,
2.45 x + 1.92(1-x) = 2
2.45 x + 1.92- 1.92x = 2
0.53 x = 0.08
or, x = 0.150 gm
So, mass of NaCl = 0.15gm
and mass of KCl = 1-x =1-0.15 = 0.85 gm