(N/A) $(i)$ Mole: One mole of any species (atoms,molecules,ions,or particles) is the quantity in number equal to Avogadro's constant $(6.022 \times 10^{23})$ having a mass equal to its atomic or molecular mass in grams.
$(ii)$ Gram atomic mass: The mass of one mole of atoms of an element expressed in grams.
$(iii)$ Gram molecular mass: The mass of one mole of molecules of a substance expressed in grams,which is the sum of the atomic masses of all atoms in the molecule.
$(b)$ $(i)$ The molar mass of $CO_2$ is $(12 + 2 \times 16) = 44 \text{ g/mol}$. Therefore,the mass of $2$ moles of $CO_2$ is $2 \times 44 = 88 \text{ g}$.
$(ii)$ Since $6.022 \times 10^{23}$ molecules represent $1$ mole of $CO_2$,the mass is equal to its molar mass,which is $44 \text{ g}$.