Phases of Matter

Q. Answer the following questions based on the P-T phase diagram of carbon dioxide: (a) At what temperature and pressure can the solid, liquid and vapour phases of CO2 co-exist in equilibrium ? (b) What is the effect of decrease of pressure on the fusion and boiling point of CO2 ? (c) What are the critical temperature and pressure for CO2 ? What is their significance ? (d) Is CO2 solid, liquid or gas at (a) –70 °C under 1 atm, (b) –60 °C under 10 atm, (c) 15 °C under 56 atm ?

Q. Answer the following questions based on the P – T phase diagram of CO2: (a) CO2 at 1 atm pressure and temperature – 60 °C is compressed isothermally. Does it go through a liquid phase ? (b) What happens when CO2 at 4 atm pressure is cooled from room temperature at constant pressure ? (c) Describe qualitatively the changes in a given mass of solid CO2 at 10 atm pressure and temperature –65 °C as it is heated up to room temperature at constant pressure. (d) CO2 is heated to a temperature 70 °C and compressed isothermally. What changes in its properties do you expect to observe ?

Q. A block of ice at $-{12}^{\circ }\text{C}$ is slowly heated and converted into steam at ${100}^{\circ }\text{C}$. Which of the following curves best represents this event?

1. 
2. 
3. 
4. 

Q. what is the difference between these 4 terms: 1)pressure 2)partial pressure 3)partial vapour pressure 4)vapour pressure

Q.

In a closed container of constant volume, the pressure of water exhibits an interesting dependence on temperature -

The point D (273.16 K, 0.006 atm) is called the triple point, Tp, of water, where all there phases coexist. What is the observed phase change when the temperature is increased from -10⁰C to +10⁰C, while maintaining a constant pressure of 0.006 atm?

1. Solid → Liquid

2. Liquid → Gas

3. Solid → Gas

4. Gas → Liquid

Q. Why in the definition of enthalpy of fusion the melting of one mole of solid substance is at STANDARD STATE and in molar enthalpy of vaporization and enthalpy of sublimation it is written that it is at constant temperature and under STANDARD PRESSURE so what is there a difference in definitions

Q. A bullet of mass $0.012kg$ and horizontal speed $70m{s}^{-1}$ strikes a block of wood of mass $0.4kg$ and instantly comes to rest with respect to the block. The block is suspended from the ceiling by means of thin wires. Calculate the height to which the block rises. Also, estimate the amount of heat produced in the block.

Q. Heat is supplied to a solid material at a constant rate. The variation of temperature of the material with heat input is as shown in the figure.The slope of DE represents:

1. Latent heat of liquid
2. Latent heat of vaporization
3. Heat capacity of vapour
4. Inverse of heat capacity of vapour