The gas among the following that can be most readily liquified is-

( Value of 'a' for NH₃ = 4.17, CO₂ = 3.59, SO₂ = 6.71, Cl₂ = 6.49)

1. NH₃

2. Cl₂

3. SO₂

4. CO₂

Van der Waals parameter 'a' signifies -

1.The magnitude of intermolecular attractive forces.

2. The magnitude of intermolecular repulsive forces.

3. The volume of a gas molecule.

4. All of the above.

The unit of van der Waals' constant 'b' is -

1. cm³ mol^-1

2. litre mol^-1

3. m³ mol^-1

4. All of the above

At moderate pressure, the van der Waal's equation becomes:

1. PV_m = RT

2. P(V_m-b) = RT

3. (P+a/V²_m) (V_m )= RT

4. P = RT/V_m + a/V²_m

Van der Waals equation at low pressure is -

1. PV = RT - Pb

2. PV = RT - $\frac{\mathrm{a}}{\mathrm{V}}$

3. PV = RT + $\frac{\mathrm{a}}{\mathrm{v}}$

4. PV = RT + Pb

At lower temperature, all gases except H₂ and He show:

1. Negative deviation

2. Positive deviation

3. Positive and negative deviation

4. None of the above

At high pressure, the compressibility factor 'Z' is equal to -

1.  Unity

$2.$ $1-\frac{\mathrm{Pb}}{\mathrm{RT}}$
$3.$ $1+\frac{\mathrm{Pb}}{\mathrm{RT}}$

4.  Zero