(a) Why does it become pleasantly warm when the lakes start freezing?
(b) Water freezes to form ice. What change would you expect in the average kinetic energy of the molecules?
(c) Which will contain more heat energy 1 g of ice at 0°C or 1 g water at 0°C?
(a) A large quantity of latent heat is released when lake water freezes, making the surroundings pleasantly warm.
(b) The average kinetic energy of the molecules decreases.
(c) 1 g of water at 0°C contains more heat energy because it releases 80 cal while forming 1 g of ice at 0°C.
More ICSE Easy level questions
85 g of water at 30°C is cooled to 5°C by adding certain mass of ice. Find the mass of ice required. [Specific heat capacity of water = 4.2 J g−1 °C−1, Specific latent heat of fusion = 336 J g−1]
During the melting of ice at 0°C: (a) energy is released and temperature remains constant (b) energy is absorbed and temperature remains constant (c) energy is absorbed and temperature rises (d) energy is released and temperature falls
fHow much heat is required to convert 500 g of ice at 0°C to water at 0°C? The latent heat of fusion of ice is 330 J g−1.
The graph given below shows heat energy supplied against change in temperature when no energy is lost to the surrounding. The slope of this graph will give: (a) specific heat capacity (b) specific latent heat of fusion (c) specific latent heat of vaporisation (d) heat capacity
Calculate the total amount of heat energy required to melt 200 g of ice at 0°C to water at 100°C. (Specific latent heat of ice = 336 J g−1, specific heat capacity of water = 4.2 J g−1 °C−1)
(a) State the principle of calorimetry. (b) Name the material used for making a calorimeter. (c) Write one characteristic property of the material chosen for making a calorimeter.
(a) A certain amount of heat will warm 1 g of material X by 10°C and 1 g of material Y by 40°C. Which material has higher specific heat capacity? (b) Which material, X or Y, would you select to make a calorimeter? (c) The specific heat capacity of a substance remains the same when it changes its state from solid to liquid. State True or False.
30 g of ice at 0°C is used to bring down the temperature of a certain mass of water at 70°C to 20°C. Find the mass of water. Specific heat capacity of water = 4.2 J g⁻¹ °C⁻¹ and specific latent heat of ice = 336 J g⁻¹.
A metal piece of mass 5 g has thermal capacity 2.5 J K⁻¹. If the mass of the metal is tripled, then its specific heat capacity will be : (a) 7.5 J K⁻¹ (b) 2.5 J K⁻¹ (c) 1.5 J g⁻¹ K⁻¹ (d) 0.5 J g⁻¹ K⁻¹
Specific heat capacity of a substance X is 1900 J kg−1 °C−1 means: (a) Substance X absorbs 1900 J for 1°C rise in temperature (b) 1 kg of substance X absorbs 1900 J heat for 1°C rise in temperature (c) 1 kg of substance X absorbs 1900 J heat to increase the temperature (d) 1 kg of substance X absorbs 1900 J heat to cool down by 1°C
Specific latent heat of a substance: (a) is directly proportional to the mass (b) is directly proportional to the change in the temperature (c) depends on the material (d) is inversely proportional to the mass
Calculate the amount of heat absorbed by 200 g of paraffin wax to melt completely at its melting point. [Specific latent heat of fusion of paraffin wax = 146 J g⁻¹]
