OCR Chemistry A – Dynamic Equilibrium (training)

Which of the following is NOT true at equilibrium?

• The forward and reverse reactions proceed at the same rate.
• The concentrations of reactants and products do not change.
• The concentration of the reactants is equal to the concentration of the products.
• The forward and reverse reactions continue to occur.

WHY is equilibrium called a dynamic state?

• The rate of reaction is fast

• The forward and backward reactions continue to take place once equilibrium is established.

• The concentrations of the reactants and products are the same

• All chemical reactions are considered to be reversible under suitable conditions.

CLOSED OR OPEN system:

Towel drying on a washing line

• CLOSED

• OPEN

• don't know :/

CLOSED OR OPEN system:

Wet towel in a sports bag

• CLOSED

• OPEN

• don't know :/

CLOSED OR OPEN system:

the human body

• CLOSED

• OPEN

• don't know :/

CLOSED OR OPEN system:

a reflux set-up

• CLOSED

• OPEN

• don't know :/

CLOSED OR OPEN system:

a distillation set-up

• CLOSED

• OPEN

• don't know :/

At what time is dynamic equilibrium established?

• 1 second

• 5 seconds

• 8 seconds

• 10 seconds

This graph shows how an equilibrium forming. 

The balanced equation is H2(g) + I2(g)  $\Longleftrightarrow$   2HI(g). 

WHICH GRAPH shows the same equilibrium forming from *pure* hydrogen iodide?

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