# What are the number of moles of 0.4g of calcium?

Apr 25, 2018

$0.01 m o {l}_{\text{Ca}}$

#### Explanation:

Remember that to find moles of a substance, multiply the mass of said substance by its molar mass.

.4g_"Ca"* (1 mol_"Ca")/(40.078g_"Ca")

The grams cancel out, leaving $\frac{.4}{40.078} = 0.01 m o {l}_{\text{Ca}}$ (1 sig fig)