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Quantum Mind
Jul2-11, 08:45 AM
1. The problem statement, all variables and given/known data
How many grams of potassium di chromate (K2Cr2O7) are present in 1 lit of its N/10 solution in acid medium?


2. Relevant equations

gram eq = NV = g/E = xg/M

3. The attempt at a solution

gram eq = NV = 0.1 * 1 = 0.1

g = gram eq * mol wt / valence factor (The valence factor I have taken as 14 because there are 7 oxygen atoms in potassium dichromate, which means in acidic solution there would be 14 H+ atoms)

0.1 * 294 / 14 = 2.1

How to proceed beyond this? The answer is one of the four:4.9, 49, 0.49, 3.9.

Quantum Mind
Jul2-11, 09:09 AM
OK, got it.

gram eq = no. of grams / Equ. wt

E = mol. wt/val factor = 294.2 / 6 = 49

g.e * E = 4.9.

Is this the answer?

Borek
Jul2-11, 09:27 AM
Looks OK to me.