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This quiz contains 8 questions from a mix of 1 subtopics.
What is the equation to calculate Gibbs free energy change, ΔG?
ΔG = T(ΔH - ΔS)
ΔG = TΔH - ΔS
ΔG = ΔH - TΔS
ΔG = ΔH + TΔS
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For a reaction to be feasible, the free energy change, ΔG, must be equal to or less than .
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What is the overall change in energy during a chemical reaction called?
enthalpy change
entropy change
free energy change
temperature change
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Calculate the free energy change, in kJ mol-1, for the following reaction above at 298 K:
MgCO3(s) ➔ MgO(s) + CO2(g) ΔH⦵ = +117 kJ mol-1, ΔS⦵ = +175 J K-1 mol-1
Give your answer to 3 significant figures.
kJ mol-1
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Why do some reactions with a negative ΔG not seem to take place?
they have a large enthalpy change
they have a large entropy change
they have a high activation energy
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What is the impact of raising the temperature on the feasibility of an exothermic reaction with a positive entropy change?
feasibility increases
feasibility decreases
feasibility stays the same
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What is the impact of lowering the temperature on the feasibility of an exothermic reaction with a negative entropy change?
feasibility decreases
feasibility stays the same
feasibility increases
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Calculate the temperature, in K, at which the following reaction becomes feasible.
WO3(s) + 3H2(g) ➔ W(s) + 3H2O(g) ΔH⦵ = +110 kJ mol-1, ΔS⦵ = +329 J K-1 mol-1
Give your answer to 3 significant figures.
K
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