Question

Calculate the number of calcium atoms in 2 g of Ca? (Atomic mass of Ca = 40 u).

Answer 1

Given

Molar mass=40gm

given mass=2gm

n(number of moles)=W (given mass)/Mo(Molar mass)=N(number of atoms)/No(Avogadro number)

2/40=N/6.023×10 ^23

N=2×6.023×10^23/40

N=3.01× 10^22