Calorimetry, Hess’s Law & Enthalpy Calculations — Drills · Grade 11 Science
Chapter: Chemical Energy & ThermodynamicsWhat these drills covers
By the end of Calorimetry, Hess’s Law & Enthalpy Calculations you should be able to:
- I can determine reaction heat from a measured surroundings change with consistent signs.
- I can add thermochemical equations and scale their enthalpy changes.
2 questions, numeric and written answer, each with a worked explanation.
Vocabulary used: calorimeter heat capacity, state function, Hess’s law.
Problem 1
Reaction warms 50 g water by 4°C; c=4.18. Find heat gained by water.
Hints
Write the relationship first; substitute with consistent units.
Answer and explanation
836 J
50×4.18×4.
Problem 2
Why reverse ΔH when reversing a reaction?
Answer and explanation
The same state difference is traversed in the opposite direction.
Response criteria
- State a scientifically accurate conclusion.
- Show the calculation or mechanism that supports it.
- Include units, conditions, or limits where relevant.