Question

Weight of $1mole$ of chlorine gas will be:
A. gram atomic weight
B. gram molecular weight
C. $71gm$
D. $35.5gm$

Answer 1

Hint: In order to answer the question, first we should know what is $1mole$ of any compound and know the unit of the weight of $1mole$ of any compound. $1mole$ of any compound is the molar mass of that compound.


Complete solution:
 The mass of one mole of chlorine gas is its molar mass. And, the mass or weight can be determined by multiplying its subscript by the molar mass of chlorine(which is the atomic weight on the periodic table in gram molecular weight). Gram molecular mass is the mass in grams of one mole of a molecular substance. Gram molecular mass is the same as molar mass.
Atomic Weight of Chlorine Gas, $C{l_2}$ = $35.45\,g\,mo{l^{ - 1}}$ .
Molar Mass of $C{l_2}$ = $2 \times 35.45\,g\,mo{l^{ - 1}}$
Molar Mass of $C{l_2}$= $71\,g\,mo{l^{ - 1}}$
And, in Gram molecular weight, the Molar Mass is $71\,g\,mo{l^{ - 1}}$ .

So the correct option is (C).

Note:The only difference is that gram molecular mass specifies the mass unit to be used. Gram molecular mass may be reported in grams or grams per mole.