Question 24
Verify by calculating that

(a) 5 moles of $C{O}_2$ and 5 moles of $H_{2}O$ do not have the same mass.

(b) 240 g calcium and 240 g magnesium elements have a mole ratio of 3:5.

(a) $C{O}_2$ has molar mass$=44gmo{l}^{-1}$

5 moles of $C{O}_2$ have molar mass$=44\times 5$$=220g$...........(i)

$H_{2}O$ has molar mass$=18gmo{l}^{-1}$

5 moles of $H_{2}O$ have mass$=18\times 5g$$=90g$............(ii)

From (i) and (ii), it is observed that both the values are not same.
Therefore, the given statement, 5 moles of $C{O}_2$ and 5 moles of $H_{2}O$ do not have the same mass, is verified.

(b) Number of moles in 240g Ca metal $=\frac{240}{40}=6$

Number of moles in 240g of Mg metal $=\frac{240}{24}=10$
Ratio = 6:10
After simplifying, ratio = 3:5
So, it is verified.