Reactions

In the Haber process, nitrogen and hydrogen are mixed at high temperature and pressure in the presence of iron. Ammonia is produced and the iron can be reused. What is the catalyst?

• Iron

• Heat

• Nitrogen

• Ammonia

What type of reaction is the combustion of fuel?

• Catalytic

• Exothermic

• Endothermic

• Thermal decomposition

Why is energy required in a chemical reaction?

• To activate a catalyst.

• To form chemical bonds.

• To break chemical bonds.

• To move molecules apart.

When green copper carbonate is heated, black copper oxide and carbon dioxide are formed. What type of reaction is this?

• Catalytic

• Exothermic

• Combustion

• Endothermic

Which of these options describes an exothermic reaction?

• The energy required to break bonds is reduced by using a catalyst.

• Less energy is released making bonds than is required to break bonds.

• More energy is released making bonds than is required to break bonds.

• More energy is released breaking bonds than is required to make bonds.

When heat is applied to a block of ice to melt it, what is happening?

• Combustion

• Physical change

• Endothermic reaction

• Thermal decomposition

If warm yeast is added to hydrogen peroxide, oxygen bubbles and water are produced and the yeast remains intact. Which substance is the reactant?

• Water

• Yeast

• Oxygen

• Hydrogen peroxide

What is required for combustion to occur that is not required for thermal decomposition?

• Heat

• Oxygen

• Catalyst

• Reactant

What energy transfer occurs in the combustion of fuel?

• Kinetic to thermal

• Chemical to kinetic

• Chemical to thermal

• Thermal to chemical

What occurs during thermal decomposition?

• A. A change in state as heat is applied.

• B. A reactant is broken down into simpler products.

• C. An exothermic reaction as a reactant is broken down.

• D. A reactant combines with oxygen to create simpler products.