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MDCAT
Chemistry
2023

Chemistry · Thermochemistry

Work through this past-paper style MCQ, then read the full explanation. Practice more chemistry questions on mMCQ with adaptive practice and topic analytics.

Question

For exothermic reactions AH°i s written as:

Options
  • A

    Zero

  • B

    Positive

  • C

    Negative

  • D

    Constant

Explanation

In an exothermic reaction, heat is released, so the enthalpy change (ΔH°) is negative.

This option is incorrect as enthalpy change is not zero during exothermic reaction.

This option is incorrect. The enthalpy change cannot be positive during exothermic process as heat is released.

This option is correct. The enthalpy change is negative during exothermic reaction as heat is released.

This option is incorrect as enthalpy change is not constant during exothermic process.

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Tagged under Chemistry · Thermochemistry · 2023