Arrange the following gases in order of their critical temperature.
NH₃, H₂O, CO₂, O₂

• NH₃ > H₂O > CO₂ > O₂

• O₂ > CO₂ > H₂O > NH₃

• H₂O > NH₃ > CO₂ > O₂

• CO₂ >O₂ >H₂O > NH₃

Assertion : At critical point the densities of substance in gaseous and liquid states are same.

Reason : Critical temperature is the temperature at which the real gas exhibit ideal behaviour for considerable range of pressure.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : In a pressure cooker, the water is brought to boil. The cooker is then removed from the stove. Now on removing the lid of pressure cooker, the water starts boiling again.

Reason: The impurities in water bring down its boiling point.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Two flasks X and Y have capacity 1L and 2L respectively and each of them contains 1 mole of a gas. The temperatures of the flasks are so adjusted that average speed of molecules in X is twice as those in Y. The pressure in flask X would be

• same as that in Y

• half of that in Y

• twice of that in Y

• 8 times ofthat in Y

A bottle of cold drink contains 200 ml liquid in which CO₂ is 0.1 molar .Suppose CO₂ behaves like an ideal gas , the volume of the dissolved CO₂ at STP is :

• 0.224 L

• 22.4 L

• 0.448 L

• 44.8 L

In the van der Waals equation, 'a' signifies

• intermolecular attraction

• intramolecular attraction

• attraction between molecules and wall of container

• volume of molecules

For a first order gas phase reaction-

A_(g) $\to$ 2B_(g) + C_(g)

P₀ be initial pressure of A and P, the total pressure at time 't'. Integrated rate equation is

• $\frac{2.303}{\mathrm{t}}\log \left(\frac{{\mathrm{P}}_0}{{\mathrm{P}}_0 - {\mathrm{P}}_{\mathrm{t}}}\right)$

• $\frac{2.303}{\mathrm{t}}\log \left(\frac{2{\mathrm{P}}_0}{3{\mathrm{P}}_0 - {\mathrm{P}}_{\mathrm{t}}}\right)$

• $\frac{2.303}{\mathrm{t}}\log \left(\frac{{\mathrm{P}}_0}{2{\mathrm{P}}_0 - {\mathrm{P}}_{\mathrm{t}}}\right)$

• $\frac{2.303}{\mathrm{t}}\log \left(\frac{2{\mathrm{P}}_0}{2{\mathrm{P}}_0 - {\mathrm{P}}_{\mathrm{t}}}\right)$

The variation of volume V, with temperature T, keeping pressure constant is called the coefficient of thermal expansion ($\mathrm{\alpha }$) of a gas, i.e., $\mathrm{\alpha }$ = $\frac{1}{\mathrm{V}}{\left(\frac{\mathrm{dV}}{\mathrm{dT}}\right)}_{\mathrm{P}}$. For an ideal gas $\mathrm{\alpha }$ is equal to

• T

• $\frac{1}{\mathrm{T}}$

• P

• $\frac{1}{\mathrm{P}}$

Equation of Boyle's law is :

• $\frac{\mathrm{dP}}{\mathrm{P}}$ = -$\frac{\mathrm{dV}}{\mathrm{V}}$

• $\frac{\mathrm{dP}}{\mathrm{P}}$ = +$\frac{\mathrm{dV}}{\mathrm{V}}$

• $\frac{{\mathrm{d}}^2\mathrm{P}}{\mathrm{P}}$ = -$\frac{\mathrm{dV}}{\mathrm{dT}}$

• $\frac{{\mathrm{d}}^2\mathrm{P}}{\mathrm{P}}$ = +$\frac{{\mathrm{d}}^2\mathrm{V}}{\mathrm{dT}}$

A radioactive sample is emitting 64 times radiations than non-hazardous limit .If its half-life is 2 hours , after what time it becomes non- hazardous ?

• 16 h

• 10 h

• 12 h

• 8 h