Catalysts

What is the main function of a catalyst in a chemical reaction?

• Increase the temperature of the system

• Lower the activation energy

• Increase the energy of the reactants

• Increase the concentration of products

How does a catalyst increase the rate of a chemical reaction?

• By changing the enthalpy of the products

• By increasing particle collisions

• By providing an alternative reaction pathway with a lower activation energy

• By raising the temperature

Which of the following is true about a catalyst?

• It is consumed in the reaction

• It increases the activation energy

• It alters the position of equilibrium

• It can be recovered chemically unchanged at the end of the reaction

In a potential energy diagram, the presence of a catalyst is shown by:

• A lower reactant energy level

• A lower activation energy peak

• A higher product energy level

• A lower product energy level

Which type of catalyst works by adsorbing reactants onto its surface?

• Biological catalyst

• Homogeneous catalyst

• Enzyme catalyst

• Heterogeneous catalyst

Why are transition metals often used as catalysts?

• They are highly reactive

• They have low melting points

• They can form variable oxidation states and complex ions

• They do not form compounds

In catalytic converters used in cars, platinum acts as a catalyst to:

• Lower fuel consumption

• Convert nitrogen to ammonia

• Convert harmful gases like CO and NO into less harmful substances

• Increase the temperature of the engine

Which of the following is not a correct statement about catalysts?

• Catalysts reduce the energy required for a reaction to proceed

• Catalysts take part in the reaction mechanism

• Catalysts alter the overall enthalpy change of the reaction

• Catalysts are not used up during the reaction

Which of the following best explains why only a small amount of catalyst is needed?

• Catalysts are very expensive

• Catalysts only work at high temperatures

• Catalysts are not used up during the reaction

• Catalysts are difficult to obtain

Which industrial process uses iron as a catalyst?

• Contact process

• Haber process

• Fermentation

• Cracking of hydrocarbons