Kinetics Thermodynamics and Equilibrium

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

• heat
• entropy
• kinetic energy
• activation energy

Systems in nature tend to undergo changes toward

• lower energy and lower entropy
•  lower energy and higher entropy
•  higher energy and lower entropy
• higher energy and higher entropy

Tags

NGSS.HS-PS3-4

A 1.0-gram piece of zinc reacts with 5 milliliters of HCl(aq). Which of these conditions of concentration and temperature would produce the greatest rate of reaction?

• 1.0 M HCl(aq) at 20.^oC
• 1.0 M HCl(aq) at 40.^oC
• 2.0 M HCl(aq) at 20.^oC
• 2.0 M HCl(aq) at 40.^oC

Tags

NGSS.HS-PS1-5

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

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

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

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-6

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

Tags

NGSS.HS-PS1-4

Given the potential energy diagram of a chemical reaction: . . . (see image)
Which arrow represents the potential energy of the reactants?

• A
• B
• C
• D

Tags

NGSS.HS-PS1-4

Given the reaction at equilibrium: 
2SO₂(g) +O₂(g) <--> 2SO₃(g) + HEAT
Which change will shift the equilibrium to the right?

• increasing the temperature
•  increasing the pressure
•  decreasing the amount of SO₂(g)
• decreasing the amount of O₂(g)

Tags

NGSS.HS-PS1-5

Which process is accompanied by a decrease in entropy?

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