Which intervals are affected by the addition of a catalyst

Foundations of Physical Science, Florida Edition

3rd EditionTom C. Hsu

1,687 solutions

Chemistry: Matter and Change

1st EditionMcGraw-Hill

4,862 solutions

Modern Chemistry

1st EditionSarquis, J., Sarquis, M.

2,184 solutions

Introductory Chemistry: A Foundation

8th EditionDonald J. DeCoste, Steven S. Zumdahl

4,874 solutions

1. Science
2. Chemistry
3. Physical Chemistry

• Flashcards

• Learn

• Test

• Match

• Flashcards

• Learn

• Test

• Match

Terms in this set (70)

Which equation represents a chemical equilibrium

1. N2(l) <-> N2(g)
2. 2NO2(g) <-> N2O4(g)
3. CO2(s) <-> CO2(g)
4. NH3(l) <-> NH3(g)

2

For a given chemical reaction, the addition of a catalyst provides a different reaction pathway that

1. decreases the reaction rate and has a higher activation energy
2. decreases the reaction rate and has a lower activation energy
3. increases the reaction rate and has a higher activation energy
4. increases the reaction rate and has a lower activation energy

4

The critical mass of nuclear reactor materials is the amount of

1. shielding material needed to reflect neutrons back into the reactor
2. moderating material needed to control the core's temperature
3. fissionable material necessary for a chain reaction to take place
4. control rods needed to absorb excess neutrons

3

A 1.0-gram strip of zinc is reacted with hydrochloric acid in a test tube. The unbalanced equation below represents the reaction

Zn(s) + HCl(aq) -> H2(g) + ZnCl2(aq)

Explain, in terms of collision theory, why using 1.0 gram of powdered zinc, instead of the 1.0 gram strip of zinc, would have increased the rate of the reaction

The greater surface area in powdered zinc would have resulted in more frequent collisions between the zinc atoms and the hydrogen ions in the HCl(aq)

Methanol can be manufactured by a reaction that is reversible. In the reaction, carbon monoxide gas and hydrogen gas react using a catalyst. The equation below represents this system at equilibrium.

CO(g) + 2H2(g) <-> CH3OH(g) + energy

Compare the rate of the forward reaction to the rate of the reverse reaction in this equilibrium.

-The rate of the forward reaction equals the rate of the reverse reaction
-both reactions occur at the same rate

does the SECOND diagram illustrate an exothermic or an endothermic reaction? State one reason, in terms of energy, to support your answer.

endothermic

-PE of product C is greater than PE of reactants A and B
-Product C absorbed energy and is at a higher PE than reactants A and B

In a nuclear reactor, a control rod is used to

1. slow down neutrons
2. speed up neutrons
3. absorb neutrons
4. produce neutrons

3

Given the equilibrium equation at 298 K:

KNO3(s) + 34.89 kJ <-(H2O)-> K+(aq) + NO3-(aq)

Describe, in terms of LeChatelier's principle, why an increase in temperature increases the solubility of KNO3.

-Increasing the temperature favors the forward, endothermic reaction, making the KNO3 dissolve into its ions
-Adding heat shifts the reaction to the right to restore equilibrium

Which lettered interval on the diagram represents the heat of reaction?

1. A
2. B
3. C
4. D

3

Given the balanced equation representing a reaction:

2HCl(aq) + Na2S2O3(aq) -> S(s) + H2SO3(aq) + 2NaCl(aq)

Decreasing the concentration of Na2S2O3(aq) decreases the rate of reaction because the:

1. activation energy decreases
2. activation energy increases
3. frequency of effective collisions decreases
4. frequency of effective collisions increases

3

Which numbered interval represents the heat of reaction?

1. 1
2. 2
3. 3
4. 4

2

An equilibrium system in a sealed, rigid container is represented by the equation below.

CO(g) + H2O(g) <-> CO2(g) + H2(g)

Compare the rate of the forward reaction to the rate of the reverse reaction at equilibrium.

-the rate of the forward reaction is equal to the rate of the reverse reaction
-the rates are the same

Based on TABLE I, which compound dissolves in water by an exothermic process?

1. NaCl
2. NaOH
3. NH4Cl
4. NH4NO3

2

Which physical changes are endothermic?

1. melting and freezing
2. melting and evaporating
3. condensation and sublimation
4. condensation and deposition

2

Many breads are made by adding yeast to dough, causing the dough to rise. Yeast is a type of microorganism that produces the catalyst zymase, which converts glucose, C6H12O6, to ethanol and carbon dioxide gas. The balanced equation for this reaction is shown below.

C6H12O6(aq) -> 2C2H5OH(aq) + 2CO2(g)

Describe how the catalyst, zymase, speeds up this reaction.

-zymase is a catalyst that provides an alternative pathway, which requires less energy
-decreases the activation energy
-changes the reaction mechanism

Given the system at equilibrium: CaSO4(s) <-> Ca2+(aq) + SO42-(aq)
If K2SO4(s) is added and the temperature remains constant, the Ca2+(aq) concentration will

1. decrease, and the amount of CaSO4(s) will decrease
2. decrease, and the amount of CaSO4(s) will increase
3. increase, and the amount of CaSO4(s) will decrease
4. increase, and the amount of CaSO4(s) will increase

2

Calcium reacts with water. This reaction is represented by the balanced equation below. The aqueous product of this reaction can be heated to evaporate the water, leaving a white solid, Ca(OH)2(s).

Ca(s) + 2H2O(l) -> Ca(OH)2(aq) + H2(g)

State one change in reaction conditions that will increase the rate of the reaction

-increase the temperature of the water
-increase the surface area of Ca(s)

Automobile catalytic converters use a platinum catalyst to reduce air pollution by changing emissions such as carbon monoxide, CO(g), into carbon dioxide, CO2(g). The uncatalyzed reaction is represented by the balanced equation below.

2CO(g) + O2(g) -> 2CO2(g) + heat

Compare the activation energy of the catalyzed reaction to the activation energy of the uncatalyzed reaction.

-the catalyzed reaction has a lower activation energy than the uncatalyzed reaction
-the activation energy is higher for the reaction with no catalyst

Given the equation representing a reaction at equilibrium:

N2(g) + 3H2(g) <-> 2NH3(g) + energy

Which change causes the equilibrium to shift to the right?

1. decreasing the concentration of H2(g)
2. decreasing the pressure
3. increasing the concentration of N2(g)
4. increasing the temperature

3

Given the balanced equation representing a reaction:

N2 + energy -> N + N

Which statement describes this reaction?

1. bonds are broken, and the reaction is endothermic
2. bonds are broken, and the reaction is exothermic
3. bond are formed, adn the reaction is endothermic
4. bonds are formed, and the reaction is exothermic

1

CH4(g) + 2O2(g) -> CO2(g) + 2H2O(g) + 890.4 kJ

Explain, in terms of collision theory, why a lower concentration of oxygen gas decreases the rate of this reaction.

-a lower concentration of oxygen gas decreases the number of effective collisions between O2 molecules and CH4 molecules

In terms of entropy and energy, systems in nature tend to undergo changes toward

1. lower entropy and lower energy
2. lower entropy and higher energy
3. higher entropy and lower energy
4. higher entropy and higher energy

3

Given the reaction at equilibrium: A(g) <-> B(g) + C(l)
Which equilibrium constant indicates an equilibrium mixture with the smallest concentration of B(g)?

1. Keq = 1.0 x 10^-10
2. Keq = 1.0 x 10^0
3. Keq = 1.0 x 10^1
4. Keq = 1.0 x 10^10

1

Which physical change is endothermic?

1. CO2(s) -> CO2(g)
2. CO2(l) -> CO2(s)
3. CO2(g) -> CO2(l)
4. CO2(g) -> CO2(s)

1

A catalyst is added to a system at equilibrium. If the temperature remains constant, the activation energy of the forward reaction

1. decreases
2. increases
3. remains the same

1

Given the balanced equation representing a reaction:

Cl2(g) -> Cl(g) + Cl(g)

What occurs during this change?

1. energy is absorbed and a bond is broken
2. energy is absorbed and a bond is formed
3. energy is released and a bond is broken
4. energy is released and a bond is formed

1

In a nuclear reactor, what does a moderator do?

1. it decreases the speed of the neutrons
2. it increases the speed of the neutrons
3. it decreases the number of neutrons
4. it increases the number of neutrons

1

Which statement best describes how a catalyst increases the rate of a reaction?

1. the catalyst provides an alternate reaction pathway with a higher activation energy
2. the catalyst provides an alternate reaction pathway with a lower activation energy
3. the catalyst provides the same reaction pathway with a higher activation energy
4. the catalyst provides the same reaction pathway with a lower activation energy

2

Assume that the potential energy of the products in a chemical reaction is 60 kilocalories. This reaction would be exothermic if the potential energy of the reactants were

1. 50 cal
2. 20 cal
3. 30 cal
4. 80 cal

4

Which phase change results in the release of energy?

1. H2O(s) -> H2O(l)
2. H2O(s) -> H2O(g)
3. H2O(l) -> H2O(g)
4. H2O(g) -> H2O(l)

4

Given the reaction:

CuSO4(s) <-> Cu2+(aq) + SO42-(aq)

The CuSO4(s) dissolves more rapidly when it is powdered because the increased surface area due to powdering permits

1. increased colvent contact
2. increased solute solubility
3. the equilibrium to shift to the left
4. the equilibrium to shift to the right

1

A few pieces of dry ice, CO2(s), at -78 degrees C are placed in a flask that contains air at 21 degrees C. The flask is sealed by placing an uninflated balloon over the mouth of the flask. As the balloon inflates, the dry ice disappears and no liquid is observed in the flask.

Compare the entropy of the CO2 molecules in the dry ice to the entropy of the CO2 molecules in the inflated balloon

-the CO2 molecules in the dry ice have less entropy than the CO2 molecules in the inflated balloon
-the CO2 gas in the balloon is more disordered
-less for CO2(s)

Step A: read the original temperature of the water
Step B: read the final temperature of the solution
Step C: pour the water into a beaker
Step D: stir the mixture
Step E: add the sodium hydroxide

What is the correct order of procedures for making this determination?

1. A -> C -> E -> B -> D
2. E -> D -> C -> A -> B
3. C -> A -> E -> D -> B
4. C -> E -> D -> A -> B

3

According to Reference Table Adv-5, when 1.0 mole of ethane is formed from its elements, 12.5 kilocalories is

1. stored as potential energy
2. given off as potential energy
3. stored as kinetic energy
4. given off as kinetic energy

1

The balanced equation below represents the reaction between a 5.0 gram sample of zinc metal and a 0.5 M solution of hydrochloric acid. The reaction takes place in an open test tube at 298 K and 1 atm in a laboratory activity.

ZN(s) + 2HCl(aq) -> H2(g) + ZnCl2(aq) + energy

Explain why this reaction will not reach equilibrium

-the H2(g) can leave the open test tube
-the reaction is driven to completion because a gas is released
-reaction not reversible

If a catalyst is added to a system at equilibrium and the temperature and pressure remain constant, there will be no effect on the

1. rate of the forward reaction
2. rate of the reverse reaction
3. activation energy of the reaction
4. heat of reaction

4

The spontaneous decay of an atom is called

1. ionization
2. crystallization
3. combustion
4. transmutation

4

Nitrogen gas, hydrogen gas, and ammonia gas are in equilibrium in a closed container at constant temperature and pressure. The equation below represents this equilibrium.

N2(g) + 3H2(g) <-> 2NH3

Explain, in terms of Le Chatelier's principle, why the final concentration of NH3(g) is greater than the initial concentration of NH3(g).

-the stress of adding H2(g) shifts the reaction to the right, producing NH3(g)
-the reaction shifts to the right to relieve the stress

According to the second law of thermodynamics, which phenomenon will most likely occur?

1. The entropy of the universe will steadily decrease
2. The universe will steadily become more disordered
3. The universe will eventually reach equilibrium at absolute zero
4. Within the universe, more heat will flow from colder to warmer regions than from warmer regions to cooler regions

2

Equilibrium can be reached by

1. physical changes, only
2. nuclear changes, only
3. both physical changes and chemical changes
4. both nuclear changes and chemical changes

3

The freezing point of bromine is

1. 539 degrees C
2. -539 degrees C
3. 7 degrees C
4. -7 degrees C

4

A cube of iron at 20 degrees C is placed in contact with a cube of copper at 60 degrees C. Which statement describes the initial flow of heat between the cubes?

1. heat flows from the copper cube to the iron cube
2. heat flows from the iron cube to the copper cube
3. heat flows in both directions between the cubes
4. heat does not flow between the cubes

1

Absolute zero represents a substance's minimum

1. internal molecular energy
2. gravitational potential energy
3. specific heat
4. heat of fusion

1

Given the reaction:

2H2(g) + O2(g) -> 2H2O(l) + 571.6 kJ

What is the approximate (delta H) for the formation of 1 mole of H2O(l)?

1. -285.8 kJ
2. +285.8 kJ
3. -571.6 kJ
4. +571.6 kJ

1

Endothermic or exothermic?

2C(s) + 2H2(g) -> C2H4(l)

endothermic

Endothermic or exothermic?

C2H5OH(l) + 3O2(g) -> 2CO2(g) + 3H2O(l)

exothermic

Endothermic or exothermic?

C6H12O6(s) + 6O2(g) -> 6CO2(g) + 6H2O(l)

exothermic

Common household bleach is an aqueous solution containing hypochlorite ions. A closed container of bleach is an equilibrium system represented by the equation below.

Cl2(g) + 2HO-(aq) <-> ClO-(aq) + Cl-(aq) + H2O(l)

Explain why the container must be closed to maintain equilibrium.

-the container must be closed so that no matter can enter or leave, thus disturbing the equilibrium
-if the container is open, Cl2 gas escapes
-to keep the concentrations of the reactants and products constant

During which change is energy absorbed?

1. the melting of ice
2. the cooling of ice
3. the freezing of water
4. the condensation of water

1

Which phase change results in an increase in entropy?

1. I2(g) -> I2(s)
2. CH4(g) -> CH4(l)
3. Br2(l) -> Br2(g)
4. H2O(l) -> H2O(s)

3

Endothermic or exothermic?

H2O(l) -> H2O(g)

endothermic

Endothermic or exothermic?

H2O(s) -> H2O(g)

endothermic

Endothermic or exothermic?

H2O(g) -> H2O(l)

exothermic

Which statement is true concerning the reaction
N(g) + N(g) -> N2(g) + energy

1. a bond is broken and energy is absorbed
2. a bond is broken and energy is released
3. a bond is formed and energy is absorbed
4. a bond is formed and energy is released

4

Which reaction will occur spontaneously? [Refer to Reference Table Adv-5]

1. .5N2(g) + .5O2(g) -> NO(g)
2. .5N2(g) + O2(g) -> NO2(g)
3. 2C(s) + 3H2(g) -> C2H6(g)
4. 2C(s) + 2H2(g) -> C2H4(g)

3

Hydrochloric acid reacts faster with powdered zinc than with an equal mass of zinc strips because the greater the surface area of the powdered zinc

1. decreases the frequency of particle collisions
2. decreases the activation energy of the reaction
3. increases the frequency of particle collisions
4. increases the activation energy of the reaction

3

Systems in nature tend to undergo changes toward

1. lower energy and lower entropy
2. lower energy and higher entropy
3. higher energy and lower entropy
4. higher energy and higher entropy

2

For a reaction system at equilibrium, LeChatelier's principle can be used to predict the

1. activation energy for the system
2. type of bonds in the reactants
3. effect of a stress on the system
4. polarity of the product molecules

3

The solid and liquid phases of water can exist in a state of equilibrium at 1 atmosphere of pressure and a temperature of

1. 0 degrees C
2. 100 degrees C
3. 273 degrees C
4. 373 degrees C

1

The entropy of a sample of H2O increases as the sample changes from a:

1. gas to a liquid
2. gas to a solid
3. liquid to a gas
4. liquid to a solid

3

When a catalyst is added to the reaction, it will change the value of

1. 1 and 2
2. 1 and 3
3. 2 and 3
4. 3 and 4

3

The effect of a catalyst on a chemical reaction is to provide a new reaction pathway that results in a different

1. potential energy of the products
2. heat of reaction
3. potential energy of the reactants
4. activation energy

4

Given the equation for a system at equilibrium:

N2(g) + 3H2(g) <-> 2NH3(g) + energy

If only the concentration of N2(g) is increased, the concentration of

1. NH3(g) increases
2. NH3(g) remains the same
3. H2(g) increases
4. H2(g) remains the same

1

Given the reaction at equilibrium: X2(g) + 2Y2(g) <-> 2XY2(g) + 80 kcal
The equilibrium will shift to the right if the pressure is

1. increased and the temperature is increased
2. increased and the temperature is decreased
3. decreased and the temperature is increased
4. decreased and the temperature is decreased

2

Two molecules of HBr collide and then form H2 and Br2-. During the collision, the bonds in the HBr molecules are

1. broken as energy is absorbed
2. broken as energy is released
3. formed as energy is absorbed
4. formed as energy is released

1

Given the equation representing a system at equilibrium:

H2O4(g) <-> 2NO2(g)

Which statement describes the concentration of the two gases in this system?

1. The concentration of N2O4(g) must be less than the concentration of NO2(g)
2. The concentration of N2O4(g) must be greater than the concentration of NO2(g)
3. The concentration of N2O4(g) and the concentration of NO2(g) must be equal
4. The concentration of N2O4(g) and the concentration of NO2(g) must be constant

4

Identify one change in the reaction conditions, other than adding a catalyst, that can increase the rate of a reaction.

-increase the temperature
-increase the pressure
-increase the concentration of H2(g)
-increase the surface area of the carbon

Which compound is formed from its elements by an exothermic reaction at 298 K and 101.3 kPa?

1. C2H4(g)
2. HI(g)
3. H2O(g)
4. NO2(g)

3

Given the equilibrium reaction at STP:

N2O4(g) <-> 2NO2(g)

Which statement correctly describes this system?

1. the forward and reverse reaction rates are equal
2. the forward and reverse reaction rates are both increasing
3. the concentration of N2O4 and NO2 are equal
4. the concentration of N2O4 and NO2 are both increasing

1

State two methods to increase the rate of a chemical reaction and explain, in terms of particle behavior, how each method increases the reaction rate.

-increasing the temperature of the reaction causes the reacting particles to move faster and collide more frequently
-increasing the concentration increases the number of particle collisions
-increasing the surface area (solid reactant) allows a greater number of particles to collide
-adding a catalyst provides an alternate way from particles to react

Chemistry: Matter and Change

1st EditionMcGraw-Hill

4,862 solutions

Foundations of Physical Science, Florida Edition

3rd EditionTom C. Hsu

1,687 solutions

ScienceFusion Grades 6-8 Module H: Matter and Energy

1st EditionHOUGHTON MIFFLIN HARCOURT

288 solutions

Chemistry: Matter and Change, California Edition

1st EditionDingrando, Gregg, Hainen, Wistrom

2,537 solutions

Reaction rates and equilibrium

30 terms

kalynkrusinski

Chemistry Ch 14 Kinetics

8 terms

MissyfeenaPLUS

Chapter 9

20 terms

paigewier

kinetics TRMC

62 terms

sarahrileeyPLUS

Organic Chemistry

14 terms

Carly_Gaul

Nine functional organic groups

9 terms

Carly_Gaul

Honors Chemistry: Kinetics and Equilibrium quiz

12 terms

Sydney_Pennell

Seven organic reactions

8 terms

Carly_Gaul

Amendments 11-27

17 terms

TaylorSt23

Bill of Rights

10 terms

TaylorSt23

Scalar v. Vector Quantities

20 terms

TaylorSt23

Variable Unites

39 terms

TaylorSt23

Surety Obstacle 3

91 terms

John_Hart367

valvular heart disease

118 terms

tiffanvn

Chem final part 1

60 terms

mitchell_rogers9

structure of the government

22 terms

leylar1

What is affected by the addition of a catalyst?

Which measurements will change with addition of a catalyst?

Which is not affected on addition of catalyst?