Change of State (Class IX)
Tests knowledge about phase changes, melting, freezing, sublimation, latent heat, and the effects of temperature and pressure on states of matter.
Questions
Which of the following will be the effect of decrease of pressure on solid carbon dioxide?
- It will freeze.
- It will turn gaseous.
- It will liquify.
- Its particles will get charged.
- Its density will increase.
Which of the following statements is/are correct?
a. Ghee has a higher melting point than mustard oil.
b. Melting point of a liquid increases with pressure.
c. Higher the inetrmolecular forces, higher the melting point.
- a only
- b only
- c only
- a and b
- a and c
Which of the following statements is/are correct?
a. Latent heat of vapourisation is the heat energy required to change 1 kg of a liquid to gas at atmospheric pressure at its boiling point.
b. Latent heat of vapourisation causes cooling.
c. Evaporation is a bulk phenomenon that afects the latent heat of vapourisation.
- a only
- b only
- c only
- a and b
- a and c
Which of the following parameters determine the physical state of matter?
a. Temperature
b. Pressure
c. Density
- a, b and c
- a and b
- a and c
- b and c
- only b
Which of the following statements is true about the effect of temperature on the state of matter?
- Increase in temperature increases the potential energy of particles in solids and liquids.
- Increase in temperature increases the kinetic energy of the particles in solids and liquids.
- Energy provided by heat increases the forces of attraction among the particles of solids and liquids.
- With an increase in temperature, the particles arrange themselves in the form of solids and liquids.
Why does the temperature remain constant during the melting of ice, although heat is continuously supplied?
- Because heat is used up in breaking the bonds between the particles
- Because heat is lost in the atmosphere
- Because heat is used up in maintaining equilibrium in the system and surroundings
- Because heat is absorbed by the container
In which of the following ways can the physical state of matter be changed?
a. It can be changed by heating or cooling the matter.
b. It can be changed by increasing or decreasing the pressure being applied on it.
c. It can be changed by increasing or decreasing the quantity of matter.
- Only a
- Only a and b
- Only b
- Only b and c
- Only c
Which of the following statements is/are false?
a. The molecules in water are tightly packed, having no spaces between them.
b. The force of attraction is maximum in the particles of solid matter and minimum in the particles of gaseous matter.
c. The molecules in a gas exert negligible small forces on each other, except during collisions.
- Only a
- Only a and b
- Only b
- Only b and c
- Only c
Freezing mixture is made up of
- ice and sugar
- water and sugar
- water and salt
- ice and common salt
What is the value of latent heat of fusion for ice?
- 30 cal per gram
- 100 cal per gram
- 80 cal per gram
- 50 cal per gram
The unit for specific latent heat is
- Jkg
- Jkg-1k-1
- Jkg-1
- JkgK-1
Which of the following conditions are required to change a gaseous state of matter into a liquid state?
- High temperature<font size="2"> and</font> low pressure
- High pressure<font size="2"> </font><font size="2"><font face="Arial" size="2"><font size="2">and</font></font></font> high temperature
- Low temperature<font size="2"> </font><font size="2"><font face="Arial" size="2"><font size="2">and</font></font></font> low pressure
- Low temperature<font size="2"> </font><font size="2"><font face="Arial" size="2"><font size="2">and</font></font></font> high pressure
Which compound of calcium is used in freezing mixture?
- Calcium chloride
- Calcium carbonate
- Calcium sulphate
- Calcium nitrate
Which of the following statements is/are false?
a. Ammonia gas can be liquified by applying high pressure and lowering the temperature.
b. Plasma is a mixture of free protons and ions.
c. The changing of vapour directly into solid is called sublimation.
- Only a
- Only a and b
- Only b
- Only b and c
- Only c
For any substance, the temperature remains the same during the change of state due to
- loss of heat
- latent heat
- less supply of heat
- lattice energy