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

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