Potassium chromate is isomorphous to potassium sulphate `(K_(2)SO_(4))`. It is found to contain `26*78 %` chromium. Calculate the atomic mass of chromium (K = `39*10`).

Options

A. `58`
B. `52`
C. `48`
D. `49`

Answer

B

Explanation

Since the forumula of potassium sulphate is `K_(2)SO_(4)` so the formula of potassium chromate is `K_(2)CrO_(4)`(`:'` it is isomorphous to `K_(2)SO_(4)`). Let atomic mass of chromium be A, then formula mass of potassium chromate should be
`= 2xx39.1+A+64 = 142.2 +A`
Percentage of `Cr = (A)/(142.2+A)xx100`
`26.78 = (A)/(142.2+A)xx100`
On solving, A = 52.00