The number of following factors which affect the percent covalent character of the ionic bond is _________

(A) Polarising power of cation

(B) Extent of distortion of anion

(C) Polarisability of the anion

(D) Polarising power of anion

$$0.5 \mathrm{~g}$$ of an organic compound $$(\mathrm{X})$$ with $$60 \%$$ carbon will produce __________ $$\times 10^{-1} \mathrm{~g}$$ of $$\mathrm{CO}_{2}$$ on complete combustion.

The titration curve of weak acid vs. strong base with phenolphthalein as indictor) is shown below. The $$\mathrm{K}_{\text {phenolphthalein }}=4 \times 10^{-10}$$.

Given: $$\log 2=0.3$$

The number of following statement/s which is/are correct about phenolphthalein is ___________

A. It can be used as an indicator for the titration of weak acid with weak base.

B. It begins to change colour at $$\mathrm{pH}=8.4$$

C. It is a weak organic base

D. It is colourless in acidic medium

When a $$60 \mathrm{~W}$$ electric heater is immersed in a gas for 100 s in a constant volume container with adiabatic walls, the temperature of the gas rises by $$5^{\circ} \mathrm{C}$$. The heat capacity of the given gas is ___________ $$\mathrm{J} \mathrm{K}^{-1}$$ (Nearest integer)