Question

How many atoms are in 163 g of calcium?

Answer 1

Answer:
`24.5* 10^(23)atoms`

Step-by-step explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number
`6.023* 10^(23)` of particles.

To calculate the number of moles, we use the equation:

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar Mass}}=(163g)/(40g/mol)=4.075moles`

1 mole of calcium contains =
`6.023* 10^(23)atoms`

Thus 4.075 moles of calcium contains =
`(6.023* 10^(23))/(1)* 4.075 =24.5* 10^(23)atoms`

Thus there are
`24.5* 10^(23)atoms` in 163 g of calcium.

Answer 2

Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles.

163 g Ca (1 mol / 40.08 g) ( 6.022 x 10^23 atoms / 1 mol ) = 2.45 x10^24 atoms Ca