Question

Molar mass: Calculating molar mass of a compound and using molar mass in math calculations

Explain in detail how to calculate the molar mass of Al(NO3)3 and K3PO4.

Answer 1

1. First determine the number atoms present of each individual element:

for \(Al(NO_3)_3\) (which means \(Al+NO_3+NO_3+NO_3\))

Total atom count: Al=1, N=3, O=9

2. From periodic table, get the molar mass of each element:

Al=26.981 g/mol
N= 14.007 g/mol
O= 15.999 g/mol

3. For each element, multiply the number of atoms by it's respective molar mass.
Add them up:

\(\underbrace{(1*26.981~g/mol)}+\underbrace{(3*14.007~g/mol)}+\underbrace{(9*15.999~g/mol)}\)=212.993 g/mol
Al N O

Molar mass of \(Al(NO_3)_3\) is 212.993 g/mol