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The average molar heat capacities of ice...

The average molar heat capacities of ice and water are respectively `37.8 (J)/(mol)` and `75.6 (J)/(mol)` and the enthalpy of fusion of ice is `6.012 (kJ)/(mol)`.The amount of heat required to change 10 g of ice at `-10^(@)C` to water at `10^(@)C` would be

A

2376 J

B

4752 J

C

3970 J

D

1128 J

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The correct Answer is:
To find the total amount of heat required to change 10 g of ice at -10°C to water at 10°C, we will break the process down into three steps: 1. Heating the ice from -10°C to 0°C. 2. Melting the ice at 0°C to water. 3. Heating the water from 0°C to 10°C. ### Step 1: Heating the Ice from -10°C to 0°C **Formula:** \[ q_1 = n \cdot C_{p, \text{ice}} \cdot \Delta T \] Where: - \( n \) = number of moles of ice - \( C_{p, \text{ice}} = 37.8 \, \text{J/(mol·°C)} \) - \( \Delta T = 0 - (-10) = 10 \, \text{°C} \) **Calculating the number of moles:** The molar mass of water (H₂O) is 18 g/mol. Thus, for 10 g of ice: \[ n = \frac{10 \, \text{g}}{18 \, \text{g/mol}} = \frac{10}{18} \, \text{mol} \approx 0.5556 \, \text{mol} \] **Calculating \( q_1 \):** \[ q_1 = 0.5556 \, \text{mol} \cdot 37.8 \, \text{J/(mol·°C)} \cdot 10 \, \text{°C} \] \[ q_1 \approx 210 \, \text{J} \] ### Step 2: Melting the Ice at 0°C **Formula:** \[ q_2 = n \cdot \Delta H_{fusion} \] Where: - \( \Delta H_{fusion} = 6.012 \, \text{kJ/mol} = 6012 \, \text{J/mol} \) **Calculating \( q_2 \):** \[ q_2 = 0.5556 \, \text{mol} \cdot 6012 \, \text{J/mol} \] \[ q_2 \approx 3340 \, \text{J} \] ### Step 3: Heating the Water from 0°C to 10°C **Formula:** \[ q_3 = n \cdot C_{p, \text{water}} \cdot \Delta T \] Where: - \( C_{p, \text{water}} = 75.6 \, \text{J/(mol·°C)} \) - \( \Delta T = 10 - 0 = 10 \, \text{°C} \) **Calculating \( q_3 \):** \[ q_3 = 0.5556 \, \text{mol} \cdot 75.6 \, \text{J/(mol·°C)} \cdot 10 \, \text{°C} \] \[ q_3 \approx 420 \, \text{J} \] ### Total Heat Required Now, we sum all the heat quantities calculated: \[ q_{total} = q_1 + q_2 + q_3 \] \[ q_{total} = 210 \, \text{J} + 3340 \, \text{J} + 420 \, \text{J} \] \[ q_{total} = 3970 \, \text{J} \] ### Final Answer The total amount of heat required to change 10 g of ice at -10°C to water at 10°C is approximately **3970 J**. ---

To find the total amount of heat required to change 10 g of ice at -10°C to water at 10°C, we will break the process down into three steps: 1. Heating the ice from -10°C to 0°C. 2. Melting the ice at 0°C to water. 3. Heating the water from 0°C to 10°C. ### Step 1: Heating the Ice from -10°C to 0°C ...
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