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 = 500 gT1​ = 19 °C → T2​ = 75 °Cq = ?

How much heat q is needed to warm 500 g of water from 19 °C to 75 °C? The specific heat of water is 4.18 J/(g·°C). Give the answer in kJ.

m = 500 gT1 = 19 °CT2 = 75 °Cc = 4.18 J/(g·°C)
q = kJ
2.Easy
waterm = 100 gT1​ = 28 °C → T2​ = 85 °Cq = ?

How much heat q is needed to warm 100 g of water from 28 °C to 85 °C? The specific heat of water is 4.18 J/(g·°C). Give the answer in kJ.

m = 100 gT1 = 28 °CT2 = 85 °Cc = 4.18 J/(g·°C)
q = kJ
3.Medium
Tf​ = ?Zincm = 50 gT = 170 °Cc = 0.388 J/(g·°C)Waterm = 200 gT = 20 °Cc = 4.18 J/(g·°C)

A 50 g block of zinc (c = 0.388 J/(g·°C)) at 170 °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 = 50 gcmetal = 0.388 J/(g·°C)Tmetal = 170 °Cmwater = 200 gTwater = 20 °Ccwater = 4.18 J/(g·°C)
Tf = °C
4.Medium
Tf​ = ?Zincm = 250 gT = 140 °Cc = 0.388 J/(g·°C)Waterm = 400 gT = 25 °Cc = 4.18 J/(g·°C)

A 250 g block of zinc (c = 0.388 J/(g·°C)) at 140 °C is dropped into 400 g of water (c = 4.18 J/(g·°C)) at 25 °C in an insulated cup. Find the final temperature Tf.

mmetal = 250 gcmetal = 0.388 J/(g·°C)Tmetal = 140 °Cmwater = 400 gTwater = 25 °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
HC3​H8​ + 5O₂reactants3CO₂ + 4H₂O(l)productsΔH° = ?

Use the standard enthalpies of formation to find ΔH° for the reaction C3H8 + 5O₂ → 3CO₂ + 4H₂O(l).

ΔH°f(C3H8) = −103.8 kJ/molΔH°f(CO₂) = −393.5 kJ/molΔH°f(H₂O, l) = −285.8 kJ/molΔH°f(O₂) = 0
ΔH° = kJ

Answer key

  1. 1. q = 117 kJ
  2. 2. q = 23.83 kJ
  3. 3. Tf = 23.4 °C
  4. 4. Tf = 31.31 °C
  5. 5. ΔH° = −1367 kJ
  6. 6. ΔH° = −2220 kJ

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