Solutions and Colloids; Reaction Rates and Equilibrium

Question 1

A solution is made by dissolving a small amount of salt in a beaker of water. The salt is referred to as the

Select one:

a. precipitate
b. filtrate
c. solvent
d. solute

Answer 1

d. solute

Question 2

Which of the following pairs can produce a homogeneous mixture?

Select one:

a. water and sand
b. oil and vinegar
c. vinegar and glucose
d. calcium carbonate and water

Answer 2

c. vinegar and glucose

Question 3

A salt sample is placed into some water and all but a small amount dissolves. The reulting solution is

Select one:

a. saturated.
b. unsaturated.
c. supersaturated.

Answer 3

a. saturated.

Question 4

You want to remove as much CO2 gas as possible from a water solution. Which of the following treatments would be most effective?

Select one:

a. cool the solution
b. filter the solution
c. boil the solution
d. shake the solution vigorously

Answer 4

c. boil the solution

Question 5

When will carbon dioxide in a carbonated soft drink dissolve best?

Select one:

a. after shaking the container
b. after heating the container
c. after cooling the container
d. after releasing the pressure

Answer 5

c. after cooling the container

Question 6

Which compound is most soluble in a polar solvent?

Select one:

a. silver nitrate
b. silver chloride
c. silver carbonate

Answer 6

a. silver nitrate

Question 7

Compared to pure water, a salt water solution will have a

Select one:

a. lower vapor pressure, freezing point and boiling point.
b. higher vapor pressure, freezing point and boiling point.
c. lower vapor pressure and freezing point and a higher boiling point.
d. higher freezing point and a lower vapor pressure and boiling point.

Answer 7

c. lower vapor pressure and freezing point and a higher boiling point.

Question 8

The boiling point of a solution is

Select one:

a. higher than that of pure solvent.
b. the same as that of pure solvent.
c. lower than that of pure solvent.
d. impossible to determine.

Answer 8

a. higher than that of pure solvent.

Question 9

The vapor pressure of a pure solvent is

Select one:

a. higher than that of a solution.
b. impossible to determine.
c. the same as that of a solution.
d. lower than that of a solution.

Answer 9

a. higher than that of a solution.

Question 10

If two solutions with concentrations of 2% sugar and 4% sugar respectively are separated by a semi permeable membrane, during osmosis, there is a new flow of

Select one:

a. sugar molucules from the concentrated to the dilute solution.
b. sugar molecules from the dilute to the concentrated solution.
c. water molecules from the concentrated to the dilute solution.
d. water molecules from the dilute to the concentrated solution.

Answer 10

d. water molecules from the dilute to the concentrated solution.

Question 11

A 100ml sample of a saturated CaSO4 solution is evaporated to dryness. The water solvent all evaporates and leaves behind a solid residue of CaSO4 that weighs 0.23 g. The CaSO4 would be classified as

Select one:

a. insoluble in water.
b. slightly soluble in water.
c. soluble in water.
d. very soluble in water.

Answer 11

b. slightly soluble in water.

Question 12

A solution is prepared by adding 25.0 mL of 1.30 M A1Cl3 solution to a flask, and then adding enough water to give a final volume of 200.0 mL. What is the molarity of the solution?

Select one:

a. 0.260
b. 0.163
c. 6.50
d. 1.24

Answer 12

b. 0.163

Question 13

A solution is made by dissolving 5.84 grams of NaCl in enough distilled water to give a final volume of 250 mL. What is the molarity of the solution?

Select one:

a. 0.100
b. 1.00
c. 0.0250
d. 0.400

Answer 13

d. 0.400

Question 14

A solution is made by combining 4.00 g of sugar and 100 mL of water of (density = 1.00 g/mL). What is the concentration in % w/w?

Select one:

a. 0.400
b. 4.00
c. 0.0400
d. 3.85

Answer 14

d. 3.85

Question 15

What volume of a 10.00% (w/v) solution is needed to provide 2.00g of sugar?

Select one:

a. 0.200 liter
b. 1.00 mL
c. 20.0 mL
d. 5.00 mL

Answer 15

c. 20.0 mL

Question 16

A solution is made by dissolving 15.0 mL of oil in enough gasoline to give 50.0 mL of solution. What is the % (v/v) of oil in the solution?

Select one:

a. 30.0
b. 23.1
c. 42.9
d. 3.33

Answer 16

a. 30.0

Question 17

How many grams of solid KCl are needed to prepare 250 mL of 0.125 M solution?

Select one:

a. 9.32
b. 31.3
c. 15.6
d. 2.33

Answer 17

d. 2.33

Question 18

How many mL of 6.00 M HC1 are needed to prepare 1500 mL of 0.500 M HC1 solution?

Select one:

a. 1.80 X 10^4
b. 125
c. 2.00 X 10^-3
d. 500

Answer 18

b. 125

Question 19

An isotonic salt solution is 0.90% (w/w) NaCl in water. How many grams of NaCl is contained in 1.00 kg of such a solution?

Select one:

a. 0.090
b. 0.90
c. 9.0
d. 90

Answer 19

c. 9.0

Question 20

What volume of ethyl alcohol is contained in 35 mL (1 oz) of 86 proof [43% (v/v] liquor?

Select one:

a. 30 mL
b. 43 mL
c. 15 mL
d. 37 mL

Answer 20

c. 15 mL

Question 21

In an exergonic process,

Select one:

a. energy is gained.
b. energy is lost.
c. energy is not gained or lost.
d. energy may be either gained or lost.

Answer 21

b. energy is lost.

Question 22

At 20oC a sample of solid spontaneously sublimes to a gas. This change in state is accompanied by which of the following changes in the sample?

Select one:

a. entropy and energy decrease
b. entropy and energy increase
c. entropy decreases and energy increases
d. energy decreases and entropy increases

Answer 22

b. entropy and energy increase

Question 23

Which of the following states of matter generally has the lowest entropy?

Select one:

a. a crystalline solid
b. a liquid
c. a gas

Answer 23

a. a crystalline solid

Question 24

Which of the following is most clearly related to the term reaction rate?

Select one:

a. temperature needed to start a reaction
b. the position of equilibrium when a reaction stops
c. the speed of a reaction
d. the spontaneous changes under the surrounding conditions

Answer 24

c. the speed of a reaction

Question 25

Which of the following is an endergonic process?

Select one:

a. exothermic reactions
b. endothermic reactions
c. equilibrium reactions
d. proposed reactions that do not proceed

Answer 25

b. endothermic reactions

Question 26

The energy required to start some spontaneous processes is called

Select one:

a. internal energy.
b. collision energy.
c. free energy.
d. activation energy.

Answer 26

d. activation energy.

Question 27

Homogeneous catalysts are thought to function by

Select one:

a. adding heat to a reaction.
b. lowering activation energy of a reaction.
c. orienting reacting molecules.
d. the collision between molecules.

Answer 27

b. lowering activation energy of a reaction.

Question 28

In a system at equilibrium it is true that

Select one:

a. the rate of the forward reaction exceeds that of the reverse.
b. the rate of the forward reaction is lower than that of the reverse reaction.
c. the rate of the reaction is equal to the rate of the reverse reaction.

Answer 28

c. the rate of the reaction is equal to the rate of the reverse reaction.

Question 29

The device used to measure heat produced or used by a chemical reaction is called a(n):

Select one:

a. thermometer
b. calorimeter
c. activator
d. Joulery

Answer 29

b. calorimeter

Question 30

A catalyzed, aqueous chemical reaction occurs. Which of the following conditions will cause the reaction to reach completion the soonest?

Select one:

a. a low concentration of catalyst
b. a high concentration of the reactants
c. a high concentration of catalyst
d. stirring the reaction mixture

Answer 30

c. a high concentration of catalyst

Question 31

Which of the following statements about a K of 3.5 calculated for a specific chemical reaction at equilibrium is incorrect?

Select one:

a. It was calculated by dividing the product of the products by that of the reactants
b. It indicates that one side of the reaction has most of the matter present
c. It is an evaluation of the extent of the two chemical reactions involved: the forward and the reverse reactions
d. a K of 3.5 indicates that a catalyst will push the reaction to the right

Answer 31

d. a K of 3.5 indicates that a catalyst will push the reaction to the right

Question 32

Sulfur reacts with oxygen to produce sulfur dioxide, but only if the high activation energy is supplied. Which condition will lower the activation energy the most?

Select one:

a. stirring the mixture
b. heating the mixture
c. using a catalyst
d. the activation evergy cannot be lowered

Answer 32

c. using a catalyst

Question 33

A reaction is spontaneous when

Select one:

a. The conditions are present for that reaction to progress and it does.
b. The conditions are at STP.
c. The conditions are such for an exothermic reaction that there is less energy in the reactants than in the products.
d. There is more than one correct response.

Answer 33

a. The conditions are present for that reaction to progress and it does.

Question 34

Which of the conditions given is necessary for a chemical reaction to occur?

Select one:

a. The molecules of the reacting chemicals must be in motion
b. The molecules of the reacting chemicals must bump into each other
c. The molecules of the reacting chemicals must be of opposite charges
d. The molecules of the reacting chemicals must be at different charges

Answer 34

b. The molecules of the reacting chemicals must bump into each other

Question 35

The following reaction is known to occur:

A + B ====== C

Suppose pure A and B was mixed. Which of the following would take place as equilibrium was established?

Select one:

a. The concentration of C would increase for a time, and then remain constant.
b. The concentration of A would increase for a time, then decrease.
c. The concentration of B would increase for a time, and then remain constant.

Answer 35

a. The concentration of C would increase for a time, and then remain constant.

Question 36

Which of the following products is not suitable to time-release method for medications that are desired to have an extended effective level time?

Select one:

a. Appetite control materials
b. Analgesics used for middle-aged people
c. Fluoride compounds in a toothpaste
d. diuretics

Answer 36

c. Fluoride compounds in a toothpaste

Question 37

Which method can be used to produce a timed-release medication?

Select one:

a. The patient is given the medication in small doses over time, rather than one larger dose.
b. The patient is to take the medication two or three times a day.
c. The medication is provided in special capsules that are subdivided into smaller, pulverized portions of the medical compound.
d. The medication compound is produced in very small amounts and each is coated with a material of varying thickness.

Answer 37

d. The medication compound is produced in very small amounts and each is coated with a material of varying thickness.

Question 38

An inhibitor will have what effect on a reaction?

Select one:

a. increase the activation energy
b. lower the activation energy
c. slow the reaction down
d. lower the amount of product produced

Answer 38

c. slow the reaction down

Question 39

Based on the following equilibrium constants, which reaction essentially goes to completion?

Reaction K

 1                         3.33 x 10^44

 2                         2.75 x 10^-36

 3                         1.00 x 10^1

 4                         1.81 x 10^0

Select one:

a. 1
b. 2
c. 3
d. 4

Answer 39

a. 1

Question 40

Ice has a(n) _____ entropy than that of liquid water.

Select one:

a. lower
b. equal
c. higher
d. can not tell

Answer 40

a. lower