Chemistry Chapter 12 - Equilibrium

Is the equilibrium constant k or K?

K

what is the speed of how fast something develops when at equilibrium

same as the speed that it breaks down at

do reactions continue to happen at equilibrium?

yes

what is Q

reaction quotient

what is the equation for the reaction quotient based on concentration?

[x]^x [D]^y / [A]^m [B]^n

when do you use the reaction quotient equation to solve for Kc?

a reversable reaction that has reached equilibrium

at a given temperature, Kc is ____

constant

what are the units of the equilibrium constant?

there are none

how to solve for Kp with pressures

Pc^x x Pd^y / PA^m x PB ^n

what state of matter can be used in a Kp equation

gasses

what happens to the Kc if initial concentration of reactants is different?

nothing

what does it mean if K »1

most of the reactants have been converted to products at equilibrium

what does it mean if K « 1

only a small proportion of the reactants have been converted to products at equilibrium

what direction will the reaction shift if Q<K

to the right

what happens to the concentration of products when a reaction shifts to the right

they increase

what happens to the concentration of reactants if a reaction shifts to the right

they decrease

what direction will the reaction shift if Q>K

to the left

what happens to the concentration of reactants if the reaction shifts to the left

increase

what happens to the concentration of products if the reaction shifts to the left

they decrease

what does it mean if Q=K

the reaction is at equilibrium

what is the coefficient rule

the coefficients are what you raise that piece of the equation to when calculating equilibrium constant

what is the reciprocal rule

the equilibrium constants for forward and reverse reactions are the reciprocals of each other

what is the rule of multiple equilibria

if a reaction can be the sum of two or more reactions (like Hess’s law), the K for the overall reaction is the product (multiply) of the equilibrium constant for the individual reactions

What is Le Chatelier’s Principle

when a chemical system at equilibrium is disturbed, it returns to equilibrium by counteracting the disturbance

what can cause a distrubance in equilibrium (three factors)

change in concentration, pressure (volume), or temperature

what happens to K when species are added or removed

nothing

For the equation 2NO + O2 = 2NO2, what direction will the reaction shift to if more O2 is added to the system?

shift right

For the equation 2NO + O2 = 2NO2, what will happen to each of the reactants and products, and K if more O2 is added to the system?

NO2 increases, NO decreases, O2 increases a lot and decreases a little, K stays the same

For the equation 2NO + O2 = 2NO2, what direction will the reaction shift to if NO is removed from the system?

shift left

For the equation 2NO + O2 = 2NO2, what will happen to each of the reactants and products, and K if NO is removed from the system?

O2 will increase, NO decreases a lot and increases a little, NO2 decreases, K stays the same

what happens to a system when total pressure is increased?

it takes place in the direction that decreases the total number of moles of gas

what happens to a system when total pressure is decreased?

it takes place in the direction that increases the total number of moles of gas

what happens to the value of K if the system is compressed or expanded?

does not change

what is it called when pressure is decreased

expansion

what is it called when pressure is increased

compression

what is an inert gas

a gas that doesn’t react

what kind of gasses are inert

nobel gasses

what happens to the equilibrium position if an inert gas is added

nothing, it increases pressure but not partial pressure

in an endothermic reaction, what direction does the equation shift if temperature increases

right

what happens to K in an endothermic reaction if T increases?

increases

what happens to the concentration of A and B in an endothermic reaction if temperature increased

they decrease

what happens to the concentration of C in an endothermic reaction if temperature increased

it increases

what direction does an equation shift towards if the reaction is endothermic and temperature decreases

shifts left

what happens to the concentration of C if the temperature of an endothermic reaction decraeses

decreases

what happens to the concentration of A and B in an endothermic reaction if the temperature increases

they increase

what happens to K in an endothermic reaction if the temperature decreased

would decrease

what direction would an exothermic reaction shift towards if temperature increased

the left

what would happen to the concentration of c in an exothermic reaction if temperature increases

decreases

what would happen to the concentration of A and B in an exothermic reaction if temperature increases

they would increase

what would happen to K in an exothermic reaction if temperature increases

it would decrease

what direction would an exothermic reaction shift towards if temperature decreased

shift right

what would happen to the concentration of C in an exothermic reaction if T decreased

it would increase

what would happen to the concentration of A and B if T decreased in an exothermic reaction

they would decrease

what would happen to k in an exothermic reaction if temperature decreased

it would increase

in an exothermic reaction, K decreases as T _________

increases

in an endothermic reaction, K increases as T ______________

increases

what effect does a catalyst have on equilibrium position?

none (does not affect shifting left or right)

what effect does a catalyst have on the equilibrium constant?

no effect

what effect does a catalyst have on the time it takes to reach equilibrium

it increases the speed

what is the I in ICE

initial (initial pressure of gas)

what is the C in ICE

change (change in pressure)

what is the E in ICE

equilibrium ( the pressure at equilibrium)

what part of ICE is used to calculate KP

E/equilibrium