15.1 Reversible Reactions & Equilibrium

Multiple Choice

What type of reactions can change products back to the their original form?

• Reversible reactions

• Irreversible reactions

• Combustion reactions

• Combination reactions

Multiple Choice

Which of the following changes is irreversible change?

• Melting of ice cube

• Heating hydrated CuSO₄

• Frying an egg

• Thermal decomposing NH₄Cl

Multiple Choice

Which of the following combination is correct?

• reversible ⇌

  irreversible →

• reversible ←

  irreversible →

• reversible ⇌

  irreversible ←

• irreversible ⇌

  reversible →

Multiple Choice

What is the color of the reactant ?

• blue

• white

Multiple Choice

forward reaction

• the substance that does the dissolving

• the reaction that forms products from reactants

• to produce

• the reaction that forms reactants from products

Multiple Choice

reverse reaction

• a substance that forms in a chemical reaction

• factors found in the built, natural, and social environments such as noise, temperature, humidity, and pressure

• a substance that takes part in and undergoes change in a chemical reaction

• the reaction that forms reactants from products

Multiple Choice

What are the two factors to look for when determining if the reaction is at equilibrium?

• Forward reaction rate is faster than the reverse reaction rate and amounts of reactants are greater than the products

• Forward and reverse reaction rates are equal and amounts of reactants and products are constant

• Forward reaction rate is slower than the reverse reaction rate and amounts of reactants are greater than the products

• Forward reaction rate is faster than the reverse reaction rate and amounts of products are greater than the reactants

Multiple Choice

When the rate of the forward reaction is equal to the rate of backward reaction, the system is said to be in

• Chemical Equilibrium

• Chemical Balance

• Chemical Constant

• Chemical Reaction

Multiple Choice

At what time does the reaction reach equilibrium?

• t₁

• t₂

• t₃

• t₄

Multiple Choice

Identify the labels (a) and (b) on the graph.

• a is the amount (concentration) of reactants and b is the concentration of products

• a is the amount (concentration) of products and b is the concentration of reactants

• a is the volume of reactants and b is the volume of products

• a is the mass of reactants and b is the mass of products

Multiple Choice

At what time (in seconds) is equilibrium established?

• 0 seconds

• 1 second

• 5 seconds

• 10 seconds

Multiple Choice

Which of the two graphs reaches equilibrium?

• The left one.

• The right one.

• Both of them.

• Neither.

Multiple Choice

Which of the following is NOT true at equilibrium?

• The forward and reverse reactions proceed at the same rate.

• The amount (concentration) of reactants and products do not change.

• The amount (concentration) of the reactants is equal to the concentration of the products.

• The forward and reverse reactions continue to occur.

Multiple Choice

During equilibrium, the amount of the products and the amount of the reactants are __________.

• equal

• constant (unchanging)

• constantly increasing

• constantly decreasing

Multiple Choice

Le Chatelier's Principle states that if a chemical system at equilibrium is stressed,

• the system will adjust to increase the stress

• the system will adjust to reduce the stress

• the system will not adjust

Multiple Choice

The following factors affect the position of equilibrium EXCEPT

• Concentration

• Pressure

• Temperature

• Catalysts

Multiple Choice

2SO_2(g)+O_2(g) ⇌ 2SO_3(g) + Heat

Adding SO_2(g) will

• shift equilibrium right

• shift equilibrium left

• increase rate of reaction

• have no change

Multiple Choice

2SO₂(g)+O₂(g) ⇌ 2SO₃(g) + Heat

Increasing the temperature will...

• shift equilibrium right

• shift equilibrium left

• increase pressure

• have no change

Multiple Choice

2SO_2(g) + O_2(g) ⇌ 2SO_3(g) + Heat

Removing O_2(g) will

• shift equilibrium right

• shift equilibrium left

• increase pressure

• have no change

Multiple Choice

2SO₂(g)+1O₂(g) ⇌ 2SO₃(g) + Heat

Increasing the pressure on the system will...

• shift equilibrium right

• shift equilibrium left

• slow rate of reaction

• have no change

Multiple Choice

For N₂ + 3H₂ →2NH₃ . When pressure is increased the equilibrium shift to right. Why?

• To increase the amount of products

• To reduce the pressure, as right has less number of moles

• K_c will increase when it is shifted to the right

• So it will increase the rate of reaction

Multiple Choice

For the reaction...
N₂  +  O₂  <=>  2NO:  Δ H = +182 kJ mol^-1.
If the temperature is increased the equilibrium position will shift _______.

• to the left

• to the right

• to the left and right

• neither left nor right