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Question
The diagram below shows a cooling curve for a substance:
- State the temperatures at which the substance condenses.
- The temperature range in which the substance is in liquid state.
- Why do we prefer ice to ice-cold water for cooling a drink?
Solution
- The substance condenses at 150°C.
- 150°C to 60°C.
- At 0°C, melting 1 g of ice into water requires 336 J of heat energy from the drink. As a result, the drink releases 336 J more heat energy than 1 g ice at 0°C. As a result, 1 g of ice at 0°C produces significantly more cooling than 1 g of water at 0°C.
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