Standard 55: Basic Equilibrium

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

• Forward reaction rate is faster than the reverse and concentrations are equal
• Forward and reverse reaction rates are equal and concentration is constant

• Forward and reverse reaction rates are equal and concentration is equal

• Forward reaction rate is faster than the reverse and concentration is equal

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

At what time the reaction reached equilibrium?

• t₁
• t₂
• t₃
• t₄

It is a chemical reaction where the reactants form products that, in turn, react together to give the reactants back.

• reversible reaction
• irreversible reaction
• decomposition reaction
• synthesis

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

• a is concentration of reactants and b is the concentration of product
• a is concentration of product and b is the concentration of reactant
• a is the volume of reactants and b is the volume of product
• a the mass of reactants and b is the mass of product

Define chemical equilibrium.

• A reaction is reversible.
• The concentration of the reactants is equal to the concentration of the products.
• The rate of a forward reaction is equal to the rate of the reverse reaction.
• The reaction stops and no further change in concentration occurs.

At what time (in seconds) is equilibrium established?

• 0 seconds
• 1 second
• 7 seconds

• 11 seconds

Which of the two graphs reaches equilibrium?

• The left one.
• The right one.
• Both of them.
• Neither.

If a reaction is reversible and has reached equilibrium, what can be said about the amounts of reactants and products?

• some reactant, some product
• no reactant, all product
• all reactant, no product

Around what time does the reaction reach equilibrium?

• 25 min

• 70 min

• 45 min

• 80 min