Chem Reactions

What is required for a chemical reaction to occur?

• standard temperature and pressure

• a catalyst added to the reaction system

• effective collisions between reactant particles

• an equal number of moles of reactants and products

As the temperature of a chemical reaction in the gas phase is increased, the rate of the reaction increases because...

• fewer particle collisions occur

• more effective particle collisions occur

• the required activation energy increases

• the concentration of the reactants increases

A chemical reaction between iron atoms and oxygen molecules can only occur if...

• the particles are heated

• the atmospheric pressure decreases

• there is a catalyst present

• there are effective collisions between the particles

A reaction is most likely to occur when reactant particles collide with...

• proper energy, only

• proper orientation, only

• both proper energy and proper orientation

• neither proper energy and proper orientation

Which event must always occur for a chemical reaction to take place?

• formation of a precipitate

• formation of a gas

• effective collisions between reacting particles

• addition of a catalyst to the reaction system

Two reactant particles collide with proper orientation. The collision will be effective if the particles have...

• high activation energy

• high ionization energy

• sufficient kinetic energy

• sufficient potential energy

As the number of effective collisions between reacting particles increases, the rate of reaction...

• decreases

• increases

• remains the same

For a reaction at equilibrium, which change can increase the rates of the forward and reserve reactions?

• a decrease in the concentration of the reactants

• a decrease in the surface area of the products

• an increase in the temperature of the system

• an increase in the activation energy of the forward reaction

Given the reaction: Mg + 2 H₂O -> Mg(OH)₂ + H₂

At which temperature will the reaction occur at the greatest rate?

• 25 degrees Celsius

• 50 degrees Celsius

• 75 degrees Celsius

• 100 degrees Celsius

Which conditions will increase the rate of a chemical reaction?

• decreased temperature and decreased concentration of reactants

• decreased temperature and increased concentration of reactants

• increased temperature and decreased concentration of reactants

• increased temperature and increased concentration of reactants