Energy from Chemicals

Which of the following statements is true?

• Bond breaking is exothermic

• Bond forming is endothermic

• Bond breaking is endothermic

• None

How does the addition of a catalyst affect a chemical reaction?

• A catalyst lowers the activation energy of a reaction

• A catalyst increases the activation energy of a reaction

• A catalyst increases the overall enthalpy change of a reaction

• A catalyst decreases the overall enthalpy change of a reaction

Which of the following is an example of an exothermic reaction?

• Combustion reaction

• Dissolving ammonium chloride in water

• Photosynthesis

• Removing water from hydrated copper (II) sulfate crystals

Which of the following is an example of an endothermic reaction?

• Photosynthesis

• Neutralisation reactions

• Reaction of metals with water

• Dissolving sodium hydroxide in water

The ΔH of an exothermic reaction is...

• positive

• negative

• neutral

The ΔH of an endothermic reaction is...

• positive

• negative

• neutral

In an endothermic reaction,

• energy needed to break the bonds is greater than energy released on forming new bonds

• energy released from forming new bonds is greater than energy needed to break the bonds

In an exothermic reaction,

• energy needed to break the bonds is greater than energy released on forming new bonds

• energy released from forming new bonds is greater than energy needed to break the bonds

This is an energy profile diagram for an...

• exothermic reaction

• endothermic reaction

• neither

This is an energy profile diagram for an...

• endothermic reaction

• exothermic reaction

• neither