Question

What is the percentage of ammonium ions in ammonium dichromate?

Answer 1

The formula unit for ammonium dichromate is `"(NH"_4)_2"Cr"_2"O"_7"`, and has a molar mass of `252.07 "g/mol"`.

The ammonium ion, `"NH"_4^+"`, is the cation, and its molar mass is `18.039 "g/mol"`. Since there are two moles of ammonium cations in one mole of ammonium dichromate, we multiply `18.039 "g/mol"xx2`, which is equal to `36.078 "g/mol"`.

To find the percentage of ammonium cations in ammonium dichromate, divide the total mass of the ammonium cations by the molar mass of ammonium dichromate and multiply times 100.

`"%NH"_4^+=(36.078 "g/mol")/(252.07 "g/mol")xx100=14.313%`