# What is the molar mass of copper(l) nitrate, #Cu(NO_3)_2#?

##### 1 Answer

The molar mass of **125.55 g/mol**

#### Explanation:

**Based on the formula you've given me, that compound would actually be copper (II) nitrate. Copper (I) nitrate is #CuNO_3#**

Before we begin here's a tip:

**atomic weight of element #xx#number of atoms given by subscript #=# molar mass**

First, you want to have your handy dandy periodic table available so you can determine the atomic weight of Cu, N, O

Cu has an atomic weight of 63.55 g/mol

N has an atomic weight of 14.01 g/mol

O has an atomic wight of 16.00 g/mol

Based on the chemical formula, we have 1 atom of **Cu**, which would have an atomic weight of 63.55 g/mol

Next, we have 1 atoms of **N**, and that has an atomic mass of 14.01 g/mol

You have 3 atoms of **O** so we would multiply the atomic mass of O by 3 to obtain 48.00 g/mol.

Now you want to add the mass of each atom together to obtain the molecular weight of the entire compound:

**63.55 g/mol + 14.01 g/mol + 48.00 g/mol** = **125.55 g/mol**