Advertisements
Advertisements
Question
Answer the following question based on the P-T phase diagram of carbon dioxide:
Is CO2 solid, liquid or gas at
- –70 °C under 1 atm,
- –60 °C under 10 atm,
- 15 °C under 56 atm?
Advertisements
Solution 1
It can be concluded from the P-T phase diagram of CO2 that:
- CO2 is gaseous at –70°C, under 1 atm pressure
- CO2 is solid at –60°C, under 10 atm pressure
- CO2 is liquid at 15°C, under 56 atm pressure
Solution 2
- The point (- 70 °C, 1.0 atm) lies in the vapour region. Hence, CO2 is vapour at this point.
- The point (- 60 °C, 10 atm) lies in the solid region. Hence, CO2 is solid at this point.
- The point (15 °C, 56 atm) lies in the liquid region. Hence, CO2 is liquid at this point
RELATED QUESTIONS
A copper block of mass 2.5 kg is heated in a furnace to a temperature of 500 °C and then placed on a large ice block. What is the maximum amount of ice that can melt? (Specific heat of copper = 0.39 J g–1 K–1; heat of fusion of water = 335 J g–1).
Answer the following questions based on the P–T phase diagram of CO2:
CO2 at 1 atm pressure and temperature – 60 °C is compressed isothermally. Does it go through a liquid phase?
Answer the following questions based on the P–T phase diagram of CO2:
What happens when CO2 at 4 atm pressure is cooled from room temperature at constant pressure?
Answer the following questions based on the P–T phase diagram of CO2:
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.
Answer the following questions based on the P–T phase diagram of CO2:
CO2 is heated to a temperature 70 °C and compressed isothermally. What changes in its properties do you expect to observe?
A ‘thermacole’ icebox is a cheap and efficient method for storing small quantities of cooked food in summer in particular. A cubical icebox of side 30 cm has a thickness of 5.0 cm. If 4.0 kg of ice is put in the box, estimate the amount of ice remaining after 6 h. The outside temperature is 45 °C, and coefficient of thermal conductivity of thermacole is 0.01 J s–1 m–1 K–1. [Heat of fusion of water = 335 × 103 J kg–1]
A brass boiler has a base area of 0.15 m2 and thickness 1.0 cm. It boils water at the rate of 6.0 kg/min when placed on a gas stove. Estimate the temperature of the part of the flame in contact with the boiler. The thermal conductivity of brass = 109 J s –1 m–1 K–1; Heat of vaporisation of water = 2256 × 103 J kg–1.
Answer the following question based on the P-T phase diagram of carbon dioxide:
At what temperature and pressure can the solid, liquid and vapour phases of CO2 co-exist in equilibrium?
Answer the following question based on the P-T phase diagram of carbon dioxide:
What is the effect of decrease of pressure on the fusion and boiling point of CO2?
Answer the following question based on the P-T phase diagram of carbon dioxide:
What are the critical temperature and pressure for CO2? What is their significance?
The radii of two copper spheres are in the ratio 1 : 3 and their temperatures are in the ratio 9 : 1. The ratio of heat content in them will be:
100 g of water is supercooled to –10°C. At this point, due to some disturbance mechanised or otherwise some of it suddenly freezes to ice. What will be the temperature of the resultant mixture and how much mass would freeze?
`[S_w = 1cal/g/^circC and L_(Fusion)^w = 80cal/g]`
Latent heat of a substance is best defined as:
What happens to temperature at 0°C during melting of ice?
Effect of increasing external pressure on boiling point:
