Chemistry · Unit 4 · Paper 3

Chemical Reactions unit test

A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.

Paper 1 Paper 2 Paper 3

Each paper is built from this unit’s 17 terms and is the same for everyone, so a teacher can assign “Unit 4, Paper 3” and every student sits the identical test. Multiple choice is marked objectively; the written sections you mark yourself against the model answer and rubric.

Suggested time 31 min 28 points0/17 attempted

Titration calculation

Net ionic equation

Percent yield

Precipitation reaction

Redox identification

Identifying reaction type

Equivalence vs endpoint

Titration

Gravimetric analysis

Back titration

Spectator ions

Stoichiometry road map

Short answer 1. Define or explain: Balancing redox in acid

3 pts

Short answer 2. Define or explain: Limiting reactant

3 pts

Short answer 3. Define or explain: Acid-base neutralization

3 pts

Short answer 4. Define or explain: Oxidation number rules

3 pts

Free response

4 pts

A student is asked to identify an unknown Group 2 metal carbonate, MCO₃. Heating 2.50 g of the compound decomposes it completely according to MCO₃(s) → MO(s) + CO₂(g), leaving 1.40 g of the metal oxide.

(a) Calculate the mass of CO₂ released.

(b) Calculate the number of moles of CO₂ released.

(d) Explain how the law of conservation of mass applies to this experiment.