Among the following, choose the ones with equal number of atoms.

A. 212 g of $\mathrm{Na}_2 \mathrm{CO}_3(\mathrm{~s})$ [molar mass $=106 \mathrm{~g}$ ]

B. 248 g of $\mathrm{Na}_2 \mathrm{O}(\mathrm{s})$ [molar mass $=62 \mathrm{~g}$ ]

C. 240 g of $\mathrm{NaOH}(\mathrm{s})$ [molar mass $=40 \mathrm{~g}$ ]

D. 12 g of $\mathrm{H}_2(\mathrm{~g})$ [molar mass $=2 \mathrm{~g}$ ]

E. 220 g of $\mathrm{CO}_2(\mathrm{~g})$ [molar mass $=44 \mathrm{~g}$ ]

Choose the correct answer from the options given below:

Dalton's Atomic theory could not explain which of the following?

The amount of glucose required to prepare $$250 \mathrm{~mL}$$ of $$\frac{\mathrm{M}}{20}$$ aqueous solution is :

(Molar mass of glucose : $$180 \mathrm{~g} \mathrm{~mol}^{-1}$$)

$$1.0 \mathrm{~g}$$ of $$\mathrm{H}_2$$ has same number of molecules as in: