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Equilibrium Chemistry Test on Wednesday! > ONE > Flashcards

Flashcards in ONE Deck (27):
1

Keq

Equilibrium Constant

2

Equilibrium Expression

Product of Products (raised to coefficient powers)

OVER

Product of Reactants (raised to coefficient powers)

3

Given: reaction is at equilibrium

Given: Keq > 1

Which side is favored: products or reactants?

 

 

 

PRODUCTS

 

If K > 1, Products are greater percentage of system

 

(If K < 1, Reactants are greater percentage of system)

4

R

I

C

E

Reaction

Initial concentrations

Change in concentrations

Equilibrium concentrations

5

If Q = Keq

Reaction is at equilibrium

6

If Q > Keq

Reaction is NOT at equilibrium

Reaction will proceed towards equilibrium by shifting Left

(If Q is BIG, products are big.  Products are STRESSED.)

 

7

If Q < Keq

Reaction is NOT at equilibrium

Reaction will proceed towards equilibrium by shifting RIGHT

(If Q is small, products are small.  Reactants are STRESSED.)

8

Law of Mass Action

9

ICE equations

 

I plus C equals E

10

LeChatelier's Principle

A change in conditions will STRESS one side of reaction.

Equilibrium will shift in to OTHER side.

11

What species are NOT included in equilibrium expression (Keq equation)?

Pure solids and pure liquids

12

First step in solving ICE problem

Balance chemical reaction!

13

Second step in solving RICE/ICE problem

Fill out RICE table

Figure out knowns and unknowns, including Keq

 

14

Third step in solving RICE/ICE problems

Write down equations (I+C=E & Keq)

Confirm # of knowns = # of unknowns

Solve for WHAT IS ASKED FOR!!

15

NH4Cl(s) ⇔ NH3(g) + HCl(g)

An increase in NH3(g) concentration put into the system STRESSES which side?

RIght (Products)

16

NH4Cl(s) ⇔ NH3(g) + HCl(g)

An increase in pressure put into the system STRESSES which side?

The side with more pressure, which is the side with more moles of gas.  The left side has zero moles of gas.  The right side has 2 moles of gas.

 

Answer: Right (Products)

17

NH4Cl(s) ⇔ NH3(g) + HCl(g)

An increase in NH3(g) concentration put into the system will shift equilibrium to which side?

Left (Reactants)

 

The right side gets stressed, which shifts the equilibrium to the left.

18

19

NH4Cl(s) ⇔ NH3(g) + HCl(g)

An increase in pressure put into the system shifts equilibrium to which side?

Increased pressure STRESSES the right side (the side with more moles of gas).  This SHIFTS the equilibrium to favor the other side more, to relieve the pressure.

 

Answer: Left (Reactants)

20

H2(g)+ I2(g)⇔ 2HI(g)+ heat

An increase in temperature (to the whole system) will STRESS which side?

Right (Products)

21

H2(g)+ I2(g)⇔ 2HI(g)+ heat

An increase in temperature (to the whole system) will SHIFT equilibrium favor to which side?

Left (Reactants)

22

Endothermic Reaction

Energy is absorbed by reactants 

Write HEAT next to reactants

positive delta H

23

Exothermic Reaction

Energy is released by products

Write HEAT next to products

negative delta H

24

Haber Process

3H2(g) + N2(g) ⇔ NH3(g) + heat

 

Fritz Haber

 

Germans used it to make explosives in WWI

 

Enabled HUGE increase in nitrogen fertilizer production which enabled HUGE increase in food production (growing crops) which enabled massive world population growth in 1900s

 

 

25

26

In Keq expression what is the concentration of H20?

1

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