A 1 kg block of ice at 0°C is placed in 2 kg of water at 80°C. What will be the final temperature of the mixture? (Assume no heat loss to the surroundings) (2019)
Practice Questions
1 question
Q1
A 1 kg block of ice at 0°C is placed in 2 kg of water at 80°C. What will be the final temperature of the mixture? (Assume no heat loss to the surroundings) (2019)
0°C
40°C
60°C
80°C
Using the principle of conservation of energy, the heat lost by water equals the heat gained by ice. The final temperature will be 0°C as the ice will melt.
Questions & Step-by-step Solutions
1 item
Q
Q: A 1 kg block of ice at 0°C is placed in 2 kg of water at 80°C. What will be the final temperature of the mixture? (Assume no heat loss to the surroundings) (2019)
Solution: Using the principle of conservation of energy, the heat lost by water equals the heat gained by ice. The final temperature will be 0°C as the ice will melt.
Steps: 8
Step 1: Understand that we have a 1 kg block of ice at 0°C and 2 kg of water at 80°C.
Step 2: Know that when the ice is placed in the water, the water will lose heat and the ice will gain heat.
Step 3: Remember that the heat lost by the water will equal the heat gained by the ice (this is called the conservation of energy).
Step 4: Realize that the ice will first melt into water at 0°C before it can increase in temperature.
Step 5: Calculate the heat needed to melt the ice: it takes 334 kJ to melt 1 kg of ice.
Step 6: Calculate the heat lost by the water as it cools down from 80°C to 0°C: it takes 2 kg of water and a specific heat capacity of 4.18 kJ/kg°C.
Step 7: Compare the heat lost by the water to the heat gained by the ice. If the heat lost by the water is enough to melt the ice, the final temperature will be 0°C.
Step 8: Conclude that since the water can provide enough heat to melt the ice, the final temperature of the mixture will be 0°C.
