alleryStart learning →For an endothermic reaction, what is the sign of the enthalpy change of the system?
AIt is negative
BIt is positive
CIt is always zero
DIt is imaginary
Answer & Solution
Correct answer: B. It is positive
1. The enthalpy change is found by subtracting the energy of the reactants from that of the products.
2. In an endothermic reaction the products hold more energy than the reactants.
3. The enthalpy change of an endothermic reaction is therefore a positive number.
4. A negative enthalpy change belongs to an exothermic reaction, which releases energy instead.
_Source: Siyavula Physical Sciences Grade 11 (Everything Science, CC BY 4.0), Chapter 12: Energy and chemical change_
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