Question:
Raunak took 5 moles of carbon atoms in a container and Krish also took 5 moles of sodium atoms in another container of same weight.
(a) Whose container is heavier?
(b) Whose container has more number of atoms?
Solution:
(a) Molar atomic mass of carbon $=12 \mathrm{~g}$
No. of moles of carbon carried by Raunak $=5$
Mass of 5 moles of carbon $=(12 \times 5)=60 \mathrm{~g}$
Molar atomic mass of sodium $=23 \mathrm{~g}$
No. of moles of sodium carried by Krish $=5$
Mass of 5 moles of sodium $=(23 \times 5)=115 \mathrm{~g}$
This shows that the container carried by Krish is heavier.
(b) Since both the containers have same number of moles, the number of atoms present in these containers are also same i.e. $5 \times N_{A}$ atoms.