Answer: There are [tex]21.08\times 10^{23}[/tex] molecules in 63.00 g of [tex]H_2O[/tex]
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{63.00g}{18g/mol}=3.5moles[/tex]
1 mole of [tex]H_2O[/tex] contains = [tex]6.023\times 10^{23}[/tex] molecules
Thus 3.5 moles of [tex]H_2O[/tex] contains = [tex]\frac{6.023\times 10^{23}}{1}\times 3.5=21.08\times 10^{23}[/tex] molecules.
There are [tex]21.08\times 10^{23}[/tex] molecules in 63.00 g of [tex]H_2O[/tex]