Answer: [tex]0.21\times 10^{22}[/tex] molecules of potassium phosphate
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{7.4g}{212g/mol}=0.035moles[/tex]
1 mole of potassium phosphate contains = [tex]6.023\times 10^{23}[/tex] molecules
0.035 mole of potassium phosphate contains = [tex]\frac{6.023\times 10^{23}}{1}\times 0.035=0.21\times 10^{23}[/tex] molecules
Thus there are [tex]0.21\times 10^{23}[/tex] molecules of potassium phosphate
