Answer
1 mol $Cl_2$ has the greater mass.
Work Step by Step
- 1 mol $Cl$
Molar mass ($Cl$) = 35.5 g/mol
Therefore, 1 mol $Cl$ = 35.5g
- 1 mol $Cl_2$
Molar mass (Cl_2) = 2 * 35.5 = 71g
Therefore, 1 mol $Cl_2$ = 71g
Since $71g > 35.5g$
The mass in 1 mol $Cl_2$ is greater.