This statement is True.
To understand why, we need to look at the molar masses of both bromine and chlorine. A mole of any substance contains the same number of molecules, which is Avogadro’s number (approximately 6.022 x 10²³ molecules). However, the weight of a mole will depend on the molar mass of the substance.
The molar mass of bromine (Br) is about 79.9 g/mol. Since bromine naturally exists as a diatomic molecule (Br2), we multiply this by 2, giving us a molar mass of approximately 159.8 g/mol for bromine gas.
On the other hand, the molar mass of chlorine (Cl) is about 35.5 g/mol, and as chlorine also exists as a diatomic molecule (Cl2), its molar mass is about 71.0 g/mol.
Since 159.8 g/mol (for Br2) is greater than 71.0 g/mol (for Cl2), we conclude that a mole of bromine gas does indeed weigh more than a mole of chlorine gas. Therefore, the statement is true.