Chem Final Study Guide

Question 1

POG: Define Kinetic Theory

Answer 1

All matter is made of tiny particles that are in constant motion.

Question 2

TF: Gases are mostly empty spaces.

Answer 2

True

Question 3

POG: Gas particles are in rapid, continuous motion, and move in straight lines.

Answer 3

True

Question 4

POG: What is compressible and what isn’t?

Answer 4

Gasses are, liquids, and solids are not.

Question 5

What is gas pressure caused by?

Answer 5

Collision of the particles on the sides of a container.
Pressure depends on:

Question 6

POG: What are the three factors for gas pressure?

Answer 6

Volume, Temperature, and Number of particles.

Question 7

What does adding more particles do to the collision and pressure?

Answer 7

Increases collision and therefore increases pressure.

Question 8

What does decreasing volume do to pressure and collision rates?

Answer 8

Decreases both of them.

Question 9

Do particles move faster at higher temperatures?

Answer 9

Yes, they do.

Question 10

What is temperature as it relates to gas pressure?

Answer 10

Temperature is the average kinetic energy of the particles in a gas.

Question 11

What is air pressure caused by?

Answer 11

The collision of the air molecules with the Earth’s surface.

Question 12

As altitude increases, air pressure. . .

Answer 12

Decreases

Question 13

What does a barometer do?

Answer 13

Measures atmospheric pressure.

Question 14

What is the Neutralization Reaction?

Answer 14

Acid + Base -> Salt + Water

Question 15

Is Salt an ionic, cation, or anion compound?

Answer 15

Ionic

Question 16

What is acid base titration used for?

Answer 16

It’s a technique used to determine the molarity of an unknown solution.

Question 17

What is the endpoint signaled through in an acid-base titration?

Answer 17

Signaled by an indicator.

Question 18

What is the color change from in a titration lab?

Answer 18

Color changes based on the acidity of the solution. This is called Phenolpthalien.

Question 19

What are the steps in an acid-base titration?

Answer 19

Buret filled with NaOH.

Flash with HCL and indicator.

Add until PALE pink color.

Question 20

Moles of Acid = Moles of Base equation.

Answer 20

MaVa=MbVb
Ma = Molarity of Acid.
Va = Volume of Acid.
Mb = Molarity of Base.
Vb = Volume of base.

Question 21

A 20 mL HCl sample required 27.4 mL of 0.15 M NaOH in a titration. Calculate the molarity of the HCL.

Answer 21

Ma(20)=(0.15)(27.4)
Ma=0.2M

Question 22

True or False: Reactants produce products and products produce reactants.

Answer 22

True

Question 23

Forward is favored -> More products

Answer 23

Reverse is favored -> more reactants

Question 24

What is the energy change for exothermic and endothermic reactions?

Answer 24

Exothermic: Activation energy for the forward reaction.

Endothermic: Activation energy for the reverse reaction.

Question 25

Equilibrium in Reactions:

Answer 25

Both reactions are occurring, they don't stop. Balance between both sides.

Question 26

What is Le Chatelier's Principle?

Answer 26

If a system at equilibrium is disturbed the equilibrium will shift to minimize the disturbance. A system at equilibrium tries to maintain the equilibrium.

Question 27

Exothermic Reactions: If the temperature increases, the reaction will shift to the. . .

Answer 27

Left

Question 28

Exothermic Reactions: If the temperature decreases, the reaction will shift to the. . .

Answer 28

Right

Question 29

Endothermic Reactions: If the temperature decreases, the reaction will shift to the. . .

Answer 29

Left

Question 30

TF: Adding a gas does not affect the equilibrium if it is not already in the equation.

Answer 30

TRUE

Question 31

Adding a catalyst does not affect the equilibrium.

Answer 31

TRUE

Question 32

The addition of a catalyst. . .

Answer 32

Speeds up forward and reverse reactions.

Question 33

What does endothermic mean?

Answer 33

Energy is absorbed.

Question 34

What does exothermic mean?

Answer 34

Energy is released.

Question 35

What is the first step in any chemical reaction?

Answer 35

Activation Energy.

Question 36

What is a catalyst?

Answer 36

Increases the rate of a reaction by lowering the activation energy. Is NOT consumed in the reaction. Overall change in energy is the same.

Question 37

What is an example of a catalyst?

Answer 37

An enzyme.

Question 38

What are the effects of a Catalyst on Activation Energy?

Answer 38

Catalysts usually speed up the reaction by lowering the activation energy for both forward and backward reactions. Catalysts decrease the activation energy needed to start a chemical reaction and increase the rate of a chemical reaction.

Question 39

What is the Reaction Rate?

Answer 39

The speed at which reactants become products. Express in terms of concentration (number of particles).

Question 40

Concentrations over time as it relates to reactants and products.

Answer 40

The amount of reactants decreases over time. The amount of products increases over time.

Question 41

What is the Collision Theory?

Answer 41

Effective collisions must have enough energy to break bonds, and they must have the correct orientation.

Question 42

What is the meaning of concentration?

Answer 42

The amount of particles in a solution.

Question 43

What two things make for Ineffective Collisions?

Answer 43

Not enough energy or wrong orientation.

Question 44

As concentration increases, the rate of reaction. . .

Answer 44

Increases

Question 45

More particles will result in . . . reactions

Answer 45

Faster

Question 46

Effect of Surface Area: What does increasing the surface area do to the reaction rate?

Answer 46

Speed it UP!

Question 47

What does the amount of particles do about the effect of surface area on reaction rates?

Answer 47

More particles will be in contact with each other so it will result in more collisions.

Question 48

Graphing rate of Reactions: Will the catalyst be graphed on a steeper slope than the control?

Answer 48

Yes, because the catalyst is faster because the same amount of products Is formed in less time.

Question 49

What is the thing used to represent REVERSIBLE REACTIONS?

Answer 49

Double arrows!

Question 50

What is the top arrow indicate?

Answer 50

Forward reaction.

Question 50

What does the bottom arrow indicate?

Answer 50

Reversible Reactions.

Question 51

What does arrows point to? A. Reactants to Products. B. Products to Reactants.

Answer 51

A. Reactants to Products.

Question 52

What is the definition of Le Chatelier's Principle?

Answer 52

Change the conditions of a reversible reaction, the position of equilibrium will shift to try and counteract the change.

Question 53

What happens to the Equilibrium when temperature is changed?

Question 54

In an EQUILIBRIUM equation, if you see (-92 kj/mol), what does this tell you?

Answer 54

It is EXOTERHMIC, because it is negative.

Question 55

If you determine one of the reactions to be EXOTHERMIC in an equilibrium equation, what does that tell you the other reaction will be by DEFAULT? A. Exothermic. B. Endothermic.

Answer 55

B. Endothermic.

Question 56

How do you determine % error? A. (Measured Value - True Value ) / True Value) * 100 B. (True - True Value ) / Measured Value) * 100

Answer 56

A. (Measured Value - True Value ) / True Value) * 100

Question 57

Percent Error Practice: In a laboratory activity, the density of a sample of vanadium is determined to be 6.7 g/cm3 at room temperature. The Merck Index reports 6.0g/cm3. What is the percent error for the determined value?

Answer 57

M=6.7g/m3 T=6.0g/com3 EQUATION: [(M-T)/T] *100 6.7 - 6.0 = .7 .7/6.0 = 0.1166 ANSWER = 12%

Question 58

Percent Error Practice: A student uses a triple beam balance and determines the mass of a metal sample to be 2.65 grams, but the actual mass is 2.82 grams. What is the student's percent error?

Answer 58

M = 2.65 grams T = 2.82 grams