Kinetics and equilibrium

Which term is defined as a measure of the disorder of a system?

• heat
• entropy
• kinetic energy
• activation energy

Which expression represents the ΔH for a chemical reaction in terms of the potential energy, PE, of its products and reactants?

•  PE of products + PE of reactants
• PE of products - PE of reactants
• PE of products × PE of reactants
• PE of products ÷ PE of reactants

Which factors must be equal in a reversible chemical reaction at equilibrium?

•  the activation energies of the forward and reverse reactions
• the rates of the forward and reverse reactions
• the concentrations of the reactants and products
•  the potential energies of the reactants and products

Given the equation representing a reaction at equilibrium:
N₂(g) + 3H₂(g) <--> 2NH₃(g) + ENERGY
Which change causes the equilibrium to shift to the right?

•  decreasing the concentration of H₂(g)
• decreasing the pressure
•  increasing the concentration of N₂(g)
• increasing the temperature

Adding a catalyst to a chemical reaction results in

•  a decrease in activation energy and a decrease in the reaction rate
• a decrease in activation energy and an increase in the reaction rate
• an increase in activation energy and a decrease in the reaction rate
• an increase in activation energy and an increase in the reaction rate

Which process is accompanied by a decrease in entropy?

• boiling of water
• condensing of water vapor
• subliming of iodine
• melting of ice

Given the reaction:
N₂(g) +O₂(g) +182.6 KJ <--> 2 NO(g)
Which change would cause an immediate increase in the rate of the forward reaction?

• increasing the concentration of NO(g)
•  increasing the concentration of N₂(g)
• decreasing the reaction temperature
•  decreasing the reaction pressure

Tags

NGSS.HS-PS1-5

Which sample has the greatest entropy?

• NH₃(g)
• NH₃(l)
• NH₃(s)
•  NH₃(aq)

Given the accompanying potential energy diagram for a reaction:
Which interval on this diagram represents the difference between the potential energy of the products and the potential energy of the reactants?

• 1
• 2
• 3
• 4

Given the reaction at equilibrium:

C₂ + D₂(g) <-->2 CD(g) + energy

Which change will cause the equilibrium to shift?

• increase in pressure

• addition of a noble gas

• addition of heat

• addition of a catalyst