Unit 7 Equilibrium

Question 1

What is the concept of equilibrium?

Answer 1

Chemical reactions can readily go both ways

Question 1

What does irreversible mean?

Answer 1

reactants can change to products, but the products can not change to reactants

Question 2

What is chemical equilibrium?

Answer 2

time in which the forward (reactant to products) and reverse (products to reactants) reactions occur at the same rate (speed)

Question 3

What is a condition of chemical equilibrium in terms of reversibility?

Answer 3

The reaction must be reversible (can go both ways)

Question 4

Is there an overall change in the concentration of the reactants and products when a reaction is at equilibrium?

Answer 4

there is no overall change in the concentration of the reactants and products

Question 5

What is the formula for Kc?

Answer 5

k=[products]/[reactants]

Question 6

What would happen to Kc if the reaction was reversed?

Answer 6

the reciprocal of the equilibrium constant

Question 7

What would multiplying the chemical reaction do to Kc ?

Answer 7

Kc super subscript to the power of what the reaction is being multiplied by

Question 8

How do you add chemical reactions?

Answer 8

eliminate species that occur on both sides

Question 9

What are the units of the equilibrium constant?

Answer 9

Equilibrium constants are unitless

Question 10

What is Heterogeneous equilibria?

Answer 10

A state of equilibrium where the reactants and products are in different states

Question 11

What is Homogenous equilibrium?

Answer 11

a state of equilibrium where the reactants and the products are in the same state

Question 12

Which type of elements are not shown in equilibrium expressions?

Answer 12

Reactants that are pure liquids (water) and solids (gold) are not shown in equilibrium expressions

Question 13

What is the formula for Kp?

Answer 13

k=(pressure of products)(pressure of reactants)

Question 14

what is a description of the Kp expression?

Answer 14

the partial pressure of the products raised to the power of their coefficients over the partial pressure of the reactants raised to the power of their coefficients

Question 15

How to find partial pressure of each species?

Answer 15

number of mols of that species over the total number of moles and multiply that by the total pressure of the system

Question 16

What is partial pressure proportional to? what is the condition to this?

Answer 16

the number of moles of gas , if the pressure and volume are held constant

Question 17

what does it mean if kc>10^3?

Answer 17

product side has higher concentration than reactant side

Question 18

what does it mean if kc<10^-3?

Answer 18

the reactant side has a higher concentration than the product side

Question 19

what does it mean if 10^-3 <Kc<10^3 ?

Answer 19

there are the same number of moles on both sides of the equations

Question 20

Which type of reaction does Equilibrium constant expression work for?

Answer 20

equilibrium reactions

Question 21

How is the equilibrium constant similar to the reaction quotient?

Answer 21

they both take the concentration of the products over the concentration of the reactant, however, the reaction quotient deal with any reactions, not only restricted to reactions at equilibrium

Question 22

What happens when the equilibrium quotient equals the equilibrium constant?

Answer 22

there is no net reaction (no overall change in the products and reactants) because the reaction is at equilibrium

Question 23

What happens when the equilibrium quotient is less than the equilibrium constant?

Answer 23

the net reaction (the overall reaction) goes from left to right ( reactants to products)

Question 24

What happens when the equilibrium quotient is greater than the equilibrium constant?

Answer 24

the net reaction( the overall reaction) goes from right to left (products to reactants)

Question 25

What is solubility?

Answer 25

the ability of a substance to dissolve

Question 26

What do ionic compounds do in solutions?

Answer 26

dissociate into ions within the solution they dissolve in

Question 27

At equilibrium, what are the concentrations of ions like?

Answer 27

concentration of ions is constant

Question 28

What is a saturated solution?

Answer 28

the maximum amount of dissolved solute a solution can hold at a particular temperature and pressure

Question 29

what is a unsaturated solution?

Answer 29

when the solution has less solute than the solution is capable of dissolving so the solute can dissolve completely

Question 30

what is a supersaturated solution?

Answer 30

when a solution contains more than the maximum amount of solute that can dissolve in a solution. the extra solute that can not dissolve will sink to the bottom of the solution forming precipitation

Question 31

What is the Ksp expression used for?

Answer 31

ion product expression

Question 32

when can we only calculate Ksp?

Answer 32

when the concentration of products is known

Question 33

What is nitrogen converted into in the Harber process? what element is used to help with this?

Answer 33

ammonia with the help of H2 help

Question 34

If stress is put on a reaction solution at equilibrium how will the reaction move?

Answer 34

will move in a direction that relieves the stress

Question 35

What are stresses that can be applied to a reaction?

Answer 35

changes in concentration, pressure, volume and temperature

Question 36

Which direction will a reaction move if moles is removed from one side?

Answer 36

reaction to move where the concentration has been removed

Question 37

Which direction will a reaction move if more moles are added to one side?

Answer 37

the reaction to move where there is less concentration

Question 38

What will lower volume do to pressure?

Answer 38

increase pressure

Question 39

What will an increase to volume do to the pressure?

Answer 39

decrease pressure

Question 40

For an exothermic reaction, how do the equilibrium constant and the temperature change? which way will the reaction move?

Answer 40

equilibrium constant decreases as the temperature increases because heat is on the product side. the reaction will move the reactant side

Question 41

For an endothermic reaction, how do the equilibrium constant and the temperature change?which way will the reaction move?

Answer 41

The equilibrium constant increases as the temperature increases. The equilibrium reaction is moving from reactants to products

Question 42

What does the amount of reactant and products depend on?

Answer 42

the energy of the reactants and products

Question 43

What do catalysts not affect?

Answer 43

the position of the equilibrium

Question 44

Do the equilibrium mixture of reactants and products occur faster or slower when a catalyst is added to the reaction?

Answer 44

faster

Question 45

What do catalysts do to the activation energy? Do they get used up during this process?

Answer 45

lower the activation energy without being used up