IB Chemistry 5.1

When an aqueous solution of sulfuric acid is added to an aqueous solution of potassium hydroxide the temperature increases. Which describes the reaction taking place?

• Exothermic, sign of ΔH +

• Exothermic, sign of ΔH −

• Endothermic, sign of ΔH +

• Endothermic, sign of ΔH −

Which statement about bond enthalpies is correct?

• Bond enthalpies have positive values for strong bonds and negative values for weak bonds.

• Bond enthalpy values are greater for ionic bonds than for covalent bonds.

• Bond breaking is endothermic and bond making is exothermic.

• The carbon–carbon bond enthalpy values are the same in ethane and ethene.

• A

• B

• C

• D

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• B

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• D

• A

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• C

• D

• A

• B

• C

• D

• A

• B

• C

• D

• A

• B

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• D

• A

• B

• C

• D