Chemistry

Assertion (A): At critical temperature liquid passes into gaseous state imperceptibly and continuously.

Reason (R) : The density of liquid and gaseous phase is equal to critical temperature.

(i) Both A and R are true and R is the correct explanation of A.

(ii) Both A and R are true but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) A is false but R is true.

Assertion (A): Gases do not liquefy above their critical temperature, even on applying high pressure.

Reason (R) : Above critical temperature, the molecular speed is high and intermolecular attractions cannot hold the molecules together because they escape because of high speed.

(i) Both A and R are true and R is the correct explanation of A.

(ii) Both A and R are true but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) A is false but R is true.

Assertion (A): The temperature at which vapour pressure of a liquid is equal to the external pressure is called boiling temperature.

Reason (R) : At high altitude atmospheric pressure is high.

(i) Both A and R are true and R is the correct explanation of A.

(ii) Both A and R are true but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) A is false but R is true.

Assertion (A): At constant temperature, pV vs V plot for real gases is not a straight line.

Reason (R) : At high pressure all gases have Z > 1 but at intermediate pressure most gases have Z < 1. 

(i) Both A and R are true and R is the correct explanation of A.

(ii) Both A and R are true but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) A is false but R is true.

In the following questions a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A): Three states of matter are the result of balance between intermolecular forces and thermal energy of the molecules.

Reason (R): Intermolecular forces tend to keep the molecules together but thermal energy of molecules tends to keep them apart.

(i) Both A and R are true and R is the correct explanation of A.

(ii) Both A and R are true but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) A is false but R is true.

Match the following graphs of ideal gas with their co-ordinates: 

Graphical representation	x and y co-ordinates
(i)	(a) pV vs. V
(ii)	(b) p vs. V
(iii)	(c) p vs.

Match the following gas laws with the equation representing them.

Match the graphs between the following variables with their names : 

Pressure versus volume graph for a real gas and an ideal gas are shown in Fig. 5.4. 

Answer the following questions on the basis of this graph. 

1. Interpret the behaviour of real gas with respect to ideal gas at low pressure. 

2. Interpret the behaviour of real gas with respect to ideal gas at high pressure. 

3. Mark the pressure and volume by drawing a line at the point where real gas behaves as an ideal gas. 

The variation of pressure with volume of the gas at different temperatures can be graphically represented as shown in Fig. 5.3.

On the basis of this graph answer the following questions.

1. How will the volume of a gas change if its pressure is increased at constant temperature? 

2. At a constant pressure, how will the volume of a gas change if the temperature is increased from 200K to 400K?