Photo AI
A block of ice at −20 °C was heated at a constant rate - Junior Cycle Science - Question d - 2017
Question d
A block of ice at −20 °C was heated at a constant rate. Its temperature was graphed against time, as shown. (i) What change of state occurs between A and B? (ii) W... show full transcript
Worked Solution & Example Answer:A block of ice at −20 °C was heated at a constant rate - Junior Cycle Science - Question d - 2017
Step 1
What change of state occurs between A and B?
Answer
Between points A and B on the graph, the change of state that occurs is from liquid (water) to gas (steam) or evaporation. Initially, the ice is heated (from -20 °C) until it reaches 0 °C, melting to water. As the heating continues, the water eventually evaporates, turning into steam at 100 °C.
Step 2
What term is used to describe the type of heat gained between A and B?
Answer
The term used to describe the type of heat gained between A and B is 'latent heat'. This is the heat required for a phase change without a change in temperature, which in this case involves the transition from liquid water to its gaseous state.