Calorimetry & enthalpy worksheet with answers

Free printable Calorimetry & enthalpy worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
waterm = 100 gq = 15 kJΔT = ?

15 kJ of heat is added to 100 g of water (c = 4.18 J/(g·°C)). Find the temperature rise ΔT.

q = 15 kJm = 100 gc = 4.18 J/(g·°C)
ΔT = °C
2.Easy
waterm = 500 gT1​ = 28 °C → T2​ = 50 °Cq = ?

How much heat q is needed to warm 500 g of water from 28 °C to 50 °C? The specific heat of water is 4.18 J/(g·°C). Give the answer in kJ.

m = 500 gT1 = 28 °CT2 = 50 °Cc = 4.18 J/(g·°C)
q = kJ
3.Medium
Tf​ = ?Ironm = 150 gT = 110 °Cc = 0.449 J/(g·°C)Waterm = 200 gT = 23 °Cc = 4.18 J/(g·°C)

A 150 g block of iron (c = 0.449 J/(g·°C)) at 110 °C is dropped into 200 g of water (c = 4.18 J/(g·°C)) at 23 °C in an insulated cup. Find the final temperature Tf.

mmetal = 150 gcmetal = 0.449 J/(g·°C)Tmetal = 110 °Cmwater = 200 gTwater = 23 °Ccwater = 4.18 J/(g·°C)
Tf = °C
4.Medium
Tf​ = ?Zincm = 250 gT = 110 °Cc = 0.388 J/(g·°C)Waterm = 200 gT = 20 °Cc = 4.18 J/(g·°C)

A 250 g block of zinc (c = 0.388 J/(g·°C)) at 110 °C is dropped into 200 g of water (c = 4.18 J/(g·°C)) at 20 °C in an insulated cup. Find the final temperature Tf.

mmetal = 250 gcmetal = 0.388 J/(g·°C)Tmetal = 110 °Cmwater = 200 gTwater = 20 °Ccwater = 4.18 J/(g·°C)
Tf = °C
5.Hard
HC2​H5​OH + 3O₂reactants2CO₂ + 3H₂O(l)productsΔH° = ?

Use the standard enthalpies of formation to find ΔH° for the reaction C2H5OH + 3O₂ → 2CO₂ + 3H₂O(l).

ΔH°f(C2H5OH) = −277.7 kJ/molΔH°f(CO₂) = −393.5 kJ/molΔH°f(H₂O, l) = −285.8 kJ/molΔH°f(O₂) = 0
ΔH° = kJ
6.Hard
H100 g C2​H6​2C2​H6​ + 7O₂reactants4CO₂ + 6H₂O(l)productsq = ?

Use the standard enthalpies of formation to find the heat q released when 100 g of C2H6 (M = 30.07 g/mol) burns completely: 2C2H6 + 7O₂ → 4CO₂ + 6H₂O(l). Give q as a positive number.

ΔH°f(C2H6) = −84.7 kJ/molΔH°f(CO₂) = −393.5 kJ/molΔH°f(H₂O, l) = −285.8 kJ/molΔH°f(O₂) = 0
q = kJ

Answer key

  1. 1. ΔT = 35.89 °C
  2. 2. q = 45.98 kJ
  3. 3. Tf = 29.49 °C
  4. 4. Tf = 29.36 °C
  5. 5. ΔH° = −1367 kJ
  6. 6. q = 5187 kJ

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