The right option for the mass of $$\mathrm{CO}_{2}$$ produced by heating $$20 \mathrm{~g}$$ of $$20 \%$$ pure limestone is

(Atomic mass of $$\mathrm{Ca}=40$$ )

$$\left[\mathrm{CaCO}_{3} \stackrel{1200 \mathrm{~K}}{\longrightarrow} \mathrm{CaO}+\mathrm{CO}_{2}\right]$$

The density of the solution is 2.15 g mL^$$-$$1, then mass of 2.5 mL solution in correct significant figures is :

What fraction of Fe exists as Fe(III) in Fe_0.96O ?

(Consider Fe_0.96O to be made up of Fe(II) and Fe(III) only)

In one molal solution that contains 0.5 mole of a solute, there is