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 gT1​ = 27 °C → T2​ = 75 °Cq = ?

How much heat q is needed to warm 100 g of water from 27 °C to 75 °C? The specific heat of water is 4.18 J/(g·°C). Give the answer in kJ.

m = 100 gT1 = 27 °CT2 = 75 °Cc = 4.18 J/(g·°C)
q = kJ
2.Easy
waterm = 300 gT1​ = 18 °C → T2​ = 95 °Cq = ?

How much heat q is needed to warm 300 g of water from 18 °C to 95 °C? The specific heat of water is 4.18 J/(g·°C). Give the answer in kJ.

m = 300 gT1 = 18 °CT2 = 95 °Cc = 4.18 J/(g·°C)
q = kJ
3.Medium
Tf​ = ?Ironm = 100 gT = 180 °Cc = 0.449 J/(g·°C)Waterm = 300 gT = 25 °Cc = 4.18 J/(g·°C)

A 100 g block of iron (c = 0.449 J/(g·°C)) at 180 °C is dropped into 300 g of water (c = 4.18 J/(g·°C)) at 25 °C in an insulated cup. Find the final temperature Tf.

mmetal = 100 gcmetal = 0.449 J/(g·°C)Tmetal = 180 °Cmwater = 300 gTwater = 25 °Ccwater = 4.18 J/(g·°C)
Tf = °C
4.Medium
Tf​ = ?Leadm = 250 gT = 140 °Cc = 0.129 J/(g·°C)Waterm = 100 gT = 16 °Cc = 4.18 J/(g·°C)

A 250 g block of lead (c = 0.129 J/(g·°C)) at 140 °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.

mmetal = 250 gcmetal = 0.129 J/(g·°C)Tmetal = 140 °Cmwater = 100 gTwater = 16 °Ccwater = 4.18 J/(g·°C)
Tf = °C
5.Hard
H2C4​H10​ + 13O₂reactants8CO₂ + 10H₂O(l)productsΔH° = ?

Use the standard enthalpies of formation to find ΔH° for the reaction 2C4H10 + 13O₂ → 8CO₂ + 10H₂O(l).

ΔH°f(C4H10) = −125.6 kJ/molΔH°f(CO₂) = −393.5 kJ/molΔH°f(H₂O, l) = −285.8 kJ/molΔH°f(O₂) = 0
ΔH° = kJ
6.Hard
H20 g C2​H5​OHC2​H5​OH + 3O₂reactants2CO₂ + 3H₂O(l)productsq = ?

Use the standard enthalpies of formation to find the heat q released when 20 g of C2H5OH (M = 46.07 g/mol) burns completely: C2H5OH + 3O₂ → 2CO₂ + 3H₂O(l). Give q as a positive number.

ΔH°f(C2H5OH) = −277.7 kJ/molΔH°f(CO₂) = −393.5 kJ/molΔH°f(H₂O, l) = −285.8 kJ/molΔH°f(O₂) = 0
q = kJ

Answer key

  1. 1. q = 20.06 kJ
  2. 2. q = 96.56 kJ
  3. 3. Tf = 30.36 °C
  4. 4. Tf = 24.88 °C
  5. 5. ΔH° = −5755 kJ
  6. 6. q = 593.3 kJ

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