Chemical Equilibrium Flashcards Preview

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Flashcards in Chemical Equilibrium Deck (28)
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0
Q

At equilibrium are the concentrations equal?

A

No, they are constant, not necessary equal

1
Q

What is equilibrium?

A

When the rate of the forward reaction equals the rate of the reverse reaction.

2
Q

What is Keq?

A

Equilibrium constant.

Concentration of the products over concentration of the reactants

3
Q

What happens when Keq is greater than 1?

A

System favours the products

4
Q

What happens when Keq is less than 1?

A

System favours reactants

5
Q

What happens when Keq equals 1?

A

Concentration of products equals concentration of reactants

6
Q

What is the mass action expression?

A

The concentration of the products raised to their coefficients over the concentration of the reactants raised to their coefficients

7
Q

What can enter the mass action expression?

A

Only aqueous and gas forms

8
Q

What is the reaction quotient?

A

Represented by Qc. Calculated by substituting the initial concentrations of the reactants and products into the equilibrium constant expression.

9
Q

What happens when Qc is less than Kc?

A

Reaction proceeds left to right to establish equilibrium

10
Q

What happens when Qc equals Kc?

A

System is at equilibrium

11
Q

What happens when Qc is greater than Kc?

A

Reaction proceeds right to left in order to establish equilibrium

12
Q

How do you calculate Keq?

A

Use the mass action expression. You may have to rearrange, set up an ice table, use variables, factor, use the quadratic formula and or the 500 rule

13
Q

How do you set up an ice table?

A

Initial concentration
Change in concentration
Equilibrium concentration

14
Q

What is the 500 rule check?

A

Take the initial concentration of reactant and divide by Keq. If this number is greater than 500, you can eliminate x in the denominator.

15
Q

What is le chateliers principle?

A

If am outside influence upsets and equilibrium, the system responds in a direction that counteracts the disturbing influence so that the equilibrium is re-established

16
Q

What factors affect equilibrium?

A

Temperature, pressure, catalyst, addition of reactant or product, addition of inert

17
Q

How does the system react to change in temperature?

A

Shifts to make more heat, or use up excess heat

18
Q

How does the system react to change in pressure?

A

If there is a decrease in pressure, shift to the side with more molecules
If there is an increase in pressure, shift to the side with fewer molecules

19
Q

How does the system react to a catalyst?

A

Causes equilibrium to be reached at a faster rate

20
Q

How does the system react to an addition of reactant or product?

A

Shift to side to use up excess

21
Q

How does the system react to a removal of react or product?

A

Shift to side to make more

22
Q

How does the system react to an addition of an inert?

A

No effect because it will collide equally with reactants and products

23
Q

What is the only factor that affects Keq? What relationship is maintained?

A

Temperature
Exothermic=inversely proportional
Endothermic=directly proportional

24
Q

What is the haber process?

A

To increase the amount of products made, the product is condensed and removed, never allowing the reaction to reach equilibrium

25
Q

What is solubility equilibrium?

A

Equilibrium that exists between and ionic solid (that has been dissolved in water) and its ions in solution

26
Q

What is ksp?

A

Solubility constant, indicates how soluble a substance is. Ksp is equal to the product of the concentration terms each raised to the power of the coefficients of the substance in the dissociation equation.
Low=not very soluble
High=soluble

27
Q

What is dynamic equilibrium?

A

All parts of the system are constantly moving in opposite directions at equal rates so that the system as a whole does not change