Which of the following compounds has the lowest melting point?

1.  ${\mathrm{CaBr}}_2$

2.  ${\mathrm{Cal}}_2$

3.  ${\mathrm{CaF}}_2$

4.  ${\mathrm{CaCl}}_2$

The most reactive compound among the following toward electrophilic aromatic substitution reaction is:

1.		2.
3.		4.

By what factor does the average velocity of a gaseous molecule increase when the temperature (in Kelvin) is doubled?

1.  2.8
2.  4.0
3.  1.4
4.  2.0

In Duma’s method of estimation of nitrogen 0.35 of an organic compound gave 55 mL of nitrogen collected at 300 K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be:
(Aqueous tension at 300K= 15 mm)

The number of geometrical isomers shown by $\left[\mathrm{Pt}\left(\mathrm{Py}\right)\left({\mathrm{NH}}_3\right)\mathrm{BrCl}\right]$ are:

Calculate the mole fraction of solute in a 1.00 molal aqueous solution.
1.  0.0177
2.  0.0344
3.  1.770
4.  0.1770

What conditions favor the formation of 2XY₄(g) in the reaction X₂(g) + 4Y₂(g) ⇋ 2XY₄(g), considering that the enthalpy change (ΔH) is negative?

The Lassaigne’s extract is boiled with conc. ${\mathrm{HNO}}_3$ while testing for halogens, because it is:

1. Helps in the precipitation of $\mathrm{AgCl}$
2. Increases the solubility product of $\mathrm{AgCl}$
3. Increases the concentration of ${\mathrm{NO}}_3^{-}$ ions
4. Decomposes ${\mathrm{Na}}_2\mathrm{S}$ and $\mathrm{NaCN}$, if formed

Find the equilibrium constant K for the reaction:

NO₂(g) ⇌ ½N₂(g) + O₂(g)

Given:

N₂(g) + O₂(g) ⇌ 2NO(g), K₁

2NO(g) + O₂(g) ⇌ 2NO₂(g), K₂