WASSCE Chemistry · Paper 1 style

Energy

One sample question with the full working. 1 more in the app, with instant feedback and repair sessions for the traps below.

A reaction that releases heat to the surroundings is

Aendothermic
Breversible
Cexothermic
Dneutral

Show the answer and working

Answer: C

Releases heat = exothermic.

Trap A Reverses a trend, direction or effect: State the rule with its direction before looking at the options (down group 1 reactivity INCREASES; exothermic forward reaction: heating shifts LEFT). An option that is the mirror image of the rule is the trap.

Trap B Picks a related substance or process with a different role: Learn reagents and processes as one-line 'name → job' cards and contrast neighbours in a table (process | product | catalyst | conditions). Match the job in the stem, not just the topic.

Trap D Gets the sign of ΔH backwards: ΔH is measured from the reaction's point of view: heat out → ΔH negative (exothermic, surroundings warm up). With bond energies, ΔH = bonds broken − bonds formed.

Traps in Energy

Reverses a trend, direction or effect
State the rule with its direction before looking at the options (down group 1 reactivity INCREASES; exothermic forward reaction: heating shifts LEFT). An option that is the mirror image of the rule is the trap.
Picks a related substance or process with a different role
Learn reagents and processes as one-line 'name → job' cards and contrast neighbours in a table (process | product | catalyst | conditions). Match the job in the stem, not just the topic.
Gets the sign of ΔH backwards
ΔH is measured from the reaction's point of view: heat out → ΔH negative (exothermic, surroundings warm up). With bond energies, ΔH = bonds broken − bonds formed.

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