How much heat q is needed to warm 150 g of water from 17 °C to 50 °C? The specific heat of water is 4.18 J/(g·°C). Give the answer in kJ.
Calorimetry & enthalpy worksheet with answers
How much heat q is needed to warm 150 g of water from 10 °C to 65 °C? The specific heat of water is 4.18 J/(g·°C). Give the answer in kJ.
A 75 g block of lead (c = 0.129 J/(g·°C)) at 80 °C is dropped into 100 g of water (c = 4.18 J/(g·°C)) at 20 °C in an insulated cup. Find the final temperature Tf.
A 200 g block of zinc (c = 0.388 J/(g·°C)) at 140 °C is dropped into 200 g of water (c = 4.18 J/(g·°C)) at 16 °C in an insulated cup. Find the final temperature Tf.
Use the standard enthalpies of formation to find the heat q released when 100 g of C2H5OH (M = 46.07 g/mol) burns completely: C2H5OH + 3O₂ → 2CO₂ + 3H₂O(l). Give q as a positive number.
Use the standard enthalpies of formation to find the heat q released when 250 g of C2H6 (M = 30.07 g/mol) burns completely: 2C2H6 + 7O₂ → 4CO₂ + 6H₂O(l). Give q as a positive number.
Answer key
- 1. q = 20.69 kJ
- 2. q = 34.48 kJ
- 3. Tf = 21.36 °C
- 4. Tf = 26.53 °C
- 5. q = 2967 kJ
- 6. q = 12967 kJ
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