When 1 kg of ice at 0 degrees Celsius absorbs 80 kilocalories of heat, the ice undergoes
a) a change of state
b) a loss of energy
c) a rise in temperature
d) an increase in volulme
The heat of fusion of water is 80 kcal/kg. That means that 1 kg of ice will melt if it absorbs 80 kcal of heat. So what do you think you should have as an answer?
Here is a clue: That is the melting point (0 C) and heat of fusion (80 KCal/kg) of ice.
A more precise way of saying what happens is "a change in phase". The volume decreases. It does not increase. The temperature remains constant during melting
Based on the given information, when 1 kg of ice at 0 degrees Celsius absorbs 80 kilocalories of heat, it undergoes a change of state. Therefore, the answer is a) a change of state.
To arrive at this answer, you can consider the heat of fusion of water, which is 80 kcal/kg. This means that 1 kg of ice will melt if it absorbs 80 kcal of heat. When the ice melts, it changes from a solid state (ice) to a liquid state (water).
Additionally, it is important to note that during the process of melting, the temperature remains constant at 0 degrees Celsius. This is because the absorbed heat is used solely to break the intermolecular forces holding the ice together, rather than increasing the temperature of the substance.
Regarding the other options:
b) a loss of energy: While energy is indeed absorbed by the ice, it does not imply a loss of energy in this context.
c) a rise in temperature: The temperature remains constant during the process of melting.
d) an increase in volume: The volume of the ice actually decreases during the melting process as it changes from a solid to a liquid state.
Therefore, the correct answer is a) a change of state.