Answer: [tex]7.36\times 10^{23}[/tex] number of molecules of chlorine gas are needed.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of sodium chloride = 35.7 g
Molar mass of sodium chloride = 58.44 g/mol
Plugging values in equation 1:
[tex]\text{Moles of sodium chloride}=\frac{35.7g}{58.44g/mol}=0.611 mol[/tex]
The given chemical equation follows:
[tex]2Na+Cl_2\rightarrow 2NaCl[/tex]
By the stoichiometry of the reaction:
If 1 mole of sodium chloride is produced from 2 moles of chlorine gas
So, 0.611 moles of sodium chloride will be produced from = [tex]\frac{2}{1}\times 0.611=1.222mol[/tex] of chlorine gas
According to the mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules
So, 1.222 moles of chlorine gas will contain = [tex]\frac{6.022\times 10^{23}}{1mol}\times 1.222mol=7.36\times 10^{23}[/tex] number of molecules
Hence, [tex]7.36\times 10^{23}[/tex] number of molecules of chlorine gas is needed.
