Kinetics & Equilibrium Review #1

A chemical reaction is most likely to occur when the colliding particles have the proper

• energy and orientation

• solubility and energy

• orientation and mass

• atomic radii and energy

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

• formation of a gas

• formation of a precipitate

• addition of a catalyst

• effective collisions between reacting particle

As the temperature of a reaction increases, it is expected that the reacting particles collide

• more often and with greater force

• more often and with less force

• less often and with greater force

• less often and with less force

At 293 K, a 1.5-gram sample of Mg ribbon reacts rapidly with 10.0 mL of 1.0 M HCl(aq). Which change in conditions would have caused the reaction to proceed more slowly?

• increasing the initial temperature to 298 K

• decreasing the concentration of HCl(aq) to 0.1 M

• using 1.5-grams of powdered magnesium

• deceasing the pressure on the system

As the concentration of reacting particles increases, the rate of reaction generally

• decreases

• increases

• remains the same

A 1.0-gram sample of Zn powder reacts faster with HCl than a single 1.0 g piece of Zn because the atoms in the powdered Zn have

• higher average kinetic energy

• lower average kinetic energy

• more contact with the H⁺ ions in the acid

• less contact with the H⁺ ions in the acid

Which will occur if a catalyst is added to a reaction mixture?

• The activation energy will be lowered

• Only the rate of the forward reaction will be increased

• Only the rate of the reverse reaction will be decreased

• The heat of reaction value will be decreased

• The reaction is exothermic because it releases heat

• The reaction is exothermic because it absorbs heat

• The reaction is endothermic because it absorbs heat

• The reaction is endothermic because it releases heat

The burning of wood is best described as an

• endothermic chemical change

• endothermic physical change

• exothermic chemical change

• exothermic physical change

• less and the reaction is exothermic

• less and the reaction is endothermic

• greater and the reaction is exothermic

• greater and the reaction is endothermic