A 2 kg piece of iron at 150°C is placed in 1 kg of water at 20°C. What will be t
Practice Questions
Q1
A 2 kg piece of iron at 150°C is placed in 1 kg of water at 20°C. What will be the final temperature of the system? (Specific heat of iron = 0.45 J/g°C, water = 4.18 J/g°C) (2023)
25°C
30°C
35°C
40°C
Questions & Step-by-Step Solutions
A 2 kg piece of iron at 150°C is placed in 1 kg of water at 20°C. What will be the final temperature of the system? (Specific heat of iron = 0.45 J/g°C, water = 4.18 J/g°C) (2023)
Step 1: Identify the mass of the iron and water. The mass of iron is 2000 grams (2 kg) and the mass of water is 1000 grams (1 kg).
Step 2: Identify the specific heat capacities. The specific heat of iron is 0.45 J/g°C and the specific heat of water is 4.18 J/g°C.
Step 3: Set up the heat transfer equation. The heat lost by the iron will equal the heat gained by the water.
Step 4: Write the equation: (mass of iron) * (specific heat of iron) * (change in temperature of iron) = (mass of water) * (specific heat of water) * (change in temperature of water).
Step 5: Define the initial temperatures: T_initial_iron = 150°C and T_initial_water = 20°C. Let T_final be the final temperature.
Step 6: Calculate the change in temperature for iron: change in temperature of iron = T_final - 150°C.
Step 7: Calculate the change in temperature for water: change in temperature of water = T_final - 20°C.
Step 8: Substitute the values into the equation: 2000 g * 0.45 J/g°C * (T_final - 150) = 1000 g * 4.18 J/g°C * (T_final - 20).
Step 9: Simplify and solve for T_final. This will involve distributing and combining like terms.
Step 10: After solving the equation, you will find that T_final is approximately 35°C.
Heat Transfer – The principle of conservation of energy where heat lost by the iron equals heat gained by the water.
Specific Heat Capacity – The amount of heat required to change the temperature of a unit mass of a substance by one degree Celsius.
Thermal Equilibrium – The state reached when two substances in contact no longer transfer heat, resulting in a common final temperature.
