Physical Science 7.4&7.5

Multiple Choice

Which of the following changes will decrease the rate of a chemical reaction?

• increasing the temperature

• grinding a reactant into a fine powder

• stirring the reaction mixture

• decreasing the concentration of one of the reactants

Multiple Choice

A reaction rate is the rate at which reactants change into products over time

• true

• false

Multiple Choice

In a chemical reaction that is at equilibrium, which of the following is true?

• All of the reactants have been converted to products

• The reaction stops even though some reactants remain

• Forward and reverse reactions occur at the same rate

• All of the products are gases

Multiple Choice

In the chemical reaction below, how could you shift the equilibrium toward water?

2H₂ (g) + O₂ (g) <--> 2H₂O (g) + heat

• increase the temperature

• increase the pressure

• decrease the amount of oxygen

• add steam to the mixture