How much heat q is needed to warm 150 g of water from 14 °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 250 g of water from 21 °C to 60 °C? The specific heat of water is 4.18 J/(g·°C). Give the answer in kJ.
A 150 g block of lead (c = 0.129 J/(g·°C)) at 170 °C is dropped into 100 g of water (c = 4.18 J/(g·°C)) at 16 °C in an insulated cup. Find the final temperature Tf.
A 50 g block of iron (c = 0.449 J/(g·°C)) at 100 °C is dropped into 400 g of water (c = 4.18 J/(g·°C)) at 23 °C in an insulated cup. Find the final temperature Tf.
Use the standard enthalpies of formation to find ΔH° for the reaction C3H8 + 5O₂ → 3CO₂ + 4H₂O(l).
Use the standard enthalpies of formation to find the heat q released when 100 g of C3H8 (M = 44.1 g/mol) burns completely: C3H8 + 5O₂ → 3CO₂ + 4H₂O(l). Give q as a positive number.
Answer key
- 1. q = 22.57 kJ
- 2. q = 40.76 kJ
- 3. Tf = 22.81 °C
- 4. Tf = 24.02 °C
- 5. ΔH° = −2220 kJ
- 6. q = 5034 kJ
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