# What is the molar mass of (NH4)2Cr207 (Ammonium dichromate)?

Dec 2, 2015

The molar mass of ammonium dichromate is $\text{252.06 g/mol}$

#### Explanation:

To calculate the molar mass of a compound, you multiply the subscripts of each element times its molar mass (atomic weight in g/mol).

$\text{(NH"_4)_2"Cr"_2"O"_7}$

When there is no written subscript, it is understood to be $1$. Also, when elements are enclosed in parentheses, the subscripts on the inside are multiplied by the number outside the parentheses.

Molar Masses of the Elements
Nitogen: $\text{14.007 g/mol}$
Hydrogen: $\text{1.00794 g/mol}$
Chromium: $\text{51.9961 g/mol}$
Oxygen: $\text{15.999 g/mol}$

Molar Mass of Ammonium Dichromate
$\left(2 \times 14.007\right) + \left(8 \times 1.00794\right) + \left(2 \times 51.9961\right) + \left(7 \times 15.999\right) = \text{252.06 g/mol}$