Question

How many moles of calcium (Ca) atoms are there in 77.4 g of Ca?

Answer 1

Lar mass of Ca = 40.08 grams/mole 77.4 g Ca * ( 1 mole Ca/ 40.08 ... n = m / M 1mol Caweights 40 gmol-1 n = 77,4 / 40 = 1.93 mol.

Answer 2

Answer: 1.94 moles

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

Given mass = 77.4 g

Molar mass = 40 g/mol

Putting in the values:

$\text{Number of moles}=\frac{77.4g}{40g/mol}=1.94$

Thus 1.94 moles of calcium atoms are there in 77.4 g of Ca.