Question

What is the percentage of cation in ammonium dichromate ?

• A. 0.1429
• B. 0.8
• C. 0.5005
• D. 0.2052

Answer 1

Answer: (A)

0.1429

Answer 2

Molecular formula of ammonium dichromate is
$(NH_4 )_2Cr_2O_7$.
Molecular weight = 2 $\times$ (14 + 4 )+ 2 $\times$ 52 + 7 $\times$ 16
= 252
Number of parts by weight of cation, i.e., $NH_4^+$
= 2 $\times$ (14 + 4) =36
% of $NH^+_4 = \frac{36}{252} \times 100 = 14.29$ %