Saskatchewan Ministry of Education Departmental Examinations Released Questions

1

Table of Contents

A.Released Questions (2016) – Chemistry 8256

1.CH30-MS1 Examine the role of valence electrons in the formation of chemical bonds.

2.CH30-MS2 Investigate how the properties of materials are dependent on their underlying intermolecular

and intramolecular forces.

3.CH30-MS3 Explore the nature and classification of organic compounds, and their uses in modern

materials.

4.CH30-EQ1 Consider the characteristics and applications of equilibrium systems in chemical reactions

5.CH30-EQ2 Analyze aqueous solution equilibria including solubility-product constants.

6.CH30-EQ3 Observe and analyze phenomena related to acid-base reactions.

7.CH30-EC1 Investigate the chemistry of oxidation and reduction (redox) reactions.

8.CH30-EC2 Examine applications of electrochemistry and their impact on society and the environment.

B.Released Questions (2016) – Chemistry 8256 Solution Pages

1.CH30-MS1 Examine the role of valence electrons in the formation of chemical bonds.

2.CH30-MS2 Investigate how the properties of materials are dependent on their underlying intermolecular

and intramolecular forces.

3.CH30-MS3 Explore the nature and classification of organic compounds, and their uses in modern

materials.

4.CH30-EQ1 Consider the characteristics and applications of equilibrium systems in chemical reactions

5.CH30-EQ2 Analyze aqueous solution equilibria including solubility-product constants.

6.CH30-EQ3 Observe and analyze phenomena related to acid-base reactions.

7.CH30-EC1 Investigate the chemistry of oxidation and reduction (redox) reactions.

8.CH30-EC2 Examine applications of electrochemistry and their impact on society and the environment.

This information package is intended for teachers preparing students for the Chemistry 30 departmental examination.

A.Released Questions (2016) – Chemistry 8256

1.CH30-MS1 Examine the role of valence electrons in the formation of chemical bonds.

1.How many valence electrons does an atom of nitrogen have?

A.3

B.5

C.7

D.15

2.An atom of magnesium combines with an atom of oxygen to form magnesium oxide, MgO. How is the bond created between the atoms?

A.The magnesium atom transfers one electron to the oxygen atom.

B.The oxygen atom transfers one electron to the magnesium atom.

C.The magnesium atom transfers two electrons to the oxygen atom.

D.The oxygen atom transfers two electrons to the magnesium atom.

3.Which of the following is the correct Lewis structure for the nitride ion,

A.

B.

C.

D.

4.Which of the following molecules has an unpaired electron?

A.

B.

C.

D.

5. Considering the octet rule, how many electrons does selenium gain to become an ion?

A. 2

B. 6

C. 8

D. 16

6.What is the correct Lewis structure for the compound

A.

B.

C.

D.

2.CH30-MS2 Investigate how the properties of materials are dependent on their underlying intermolecular and intramolecular forces.

1.Ethene is a gas with a very low boiling point. Its structural formula is

Which intermolecular forces are present in a sample of ethene molecules?

A.dispersion forces only

B.dispersion forces and hydrogen bonding

C.dispersion forces and dipole-dipole attractions

D.dispersion forces, hydrogen bonding, and dipole-dipole attractions

2.Which of the following is an intramolecular force?

A.metallic bonding

B.network-covalent

C.hydrogen bonding

D.van der Waals force

3.Which of the following substances has the lowest boiling point?

A.

B.

C.

D.

3.CH30-MS3 Explore the nature and classification of organic compounds, and their uses in modern materials.

NR1How many total bonds are present in a molecule of pentane?

(Record your answer in the numeric response section on the answer sheet.)

1.Consider the following organic compounds:

i

ii

iii

iv

Which ones are isomers?

A.i and ii

B.ii and iii

C.iii and iv

D.i and iv

2.Consider the following compound.

What is the molecule’s IUPAC name?

A.3, 4 – dimethylpentene

B.2, 3 – dimethylpentene

C.3, 4 – dimethyl–3–pentene

D.2, 3 – dimethyl–2–pentene

3.Which of the following compounds is an alcohol?

A.

B.

C.

D.

4.Consider the following organic compound:

What is the molecule’s IUPAC name?

A.2–hexyne

B.3–hexyne

C.4–hexyne

D.5–hexyne

NR2How many hydrogen atoms are present in a molecule of
2,3–dimethyl–2–pentene?

(Record your answer in the numeric response section on the answer sheet.)

5.How many straight or branched-chain isomers can be made for the organic compound

A.3

B.4

C.5

D.6

6.Which of the following compounds is an ether?

A.

B.

C.

D.

4.CH30-EQ1 Consider the characteristics and applications of equilibrium systems in chemical reactions

1.Ethanol, can be manufactured by reacting ethane and water vapour in the presence of a phosphoric acid catalyst.

What condition will lead to an increased production of ethanol?

A.low pressure, low temperature

B.low pressure, high temperature

C.high pressure, low temperature

D.high pressure, high temperature

NR1.Sulphur dioxide forms sulphur trioxide according to the following equation:

At a certain temperature, after equilibrium has been reached, the concentrations of reactants and product were found to be the following:

What is the numerical value of the equilibrium constant, for this system?

(Record your answer in the numeric response section on the answer sheet.)

2.and are placed in a flask held at 200 °C. The system is allowed to reach equilibrium.

What will happen when more is added to the equilibrium system?

A.no effect on the system

B.more heat will be produced

C.the amount of will decrease

D.the amount of will decrease

3.The graph shown represents the chemical system

What is the most appropriate conclusion that can be drawn from the graph?

A.A catalyst was used to obtain equilibrium.

B.At equilibrium, reactants are favoured over products.

C.At equilibrium, products are favoured over reactants.

D.At equilibrium, neither reactants nor products are favoured.

4.Methyl alcohol is the compound from which formaldehyde, acetic acid, antifreeze, and many dyes are synthesized.

To produce methyl alcohol, carbon monoxide is reacted with hydrogen.

A chemist began with and When the reaction reached equilibrium at 1050 °C, the concentration of was found to be mol/L.

According to the above information, what is the equilibrium concentration of

A. mol/L

B. mol/L

C. mol/L

D. mol/L

5.Why is chemical equilibrium referred to as dynamic?

A.the equilibrium constant changes

B.reactants and products keep reacting

C.rates of the forward and reverse reactions change

D.concentrations of the reactants and products continue to change

6.For which of the following values of will the corresponding mixture consist almost entirely of reactants?

A.

B.

C.

D.

7.Consider the following equilibrium expression:

Which of the following equilibrium constant expressions would be appropriate for the equilibrium?

A.Keq

B. Keq

C.Keq

D.Keq

NR2.Consider the following equilibrium equation:

The equilibrium concentrations for all molecules involved are:

What is the value of the equilibrium constant for the reaction?

(Record your answer in the numeric response section on the answer sheet.)

8.At constant temperature, for which of the following systems at equilibrium will decreasing the pressure cause a shift to the right?

A.

B.

C.

D.

9.Nitric acid is commonly used as a fertilizer but is also used as an oxidizer in rocket fuel, in woodworking and in making jewelry. It is produced using the Ostwald process where the first step is an equilibrium involving the decomposition of ammonia according to the equation:

According to LeChatelier’s principle, which of the following stresses would shift the equilibrium to increase the production of

A.decrease pressure

B.decrease temperature

C.increase the concentration of

D.decrease the concentration of

10.The equilibrium system was established in a closed container. The following graph illustrates
changes in the equilibrium as a result of changes to the system.

What possible stress was applied at t = 6.00 min?

A.Some was added to the system.

B.The temperature was increased.

C.The volume was increased.

D.A catalyst was added.

11.Sulfur dioxide forms sulfur trioxide according to the following equation:

Initially, and When equilibrium is established,

What is the value of the equilibrium concentration of ?

A.0.12 M

B.0.185 M

C.0.315 M

D.0.370 M

5.CH30-EQ2 Analyze aqueous solution equilibria including solubility-product constants.

Use the following information for questions 1 and NR1.

Solubility charts, like the one shown, are a convenient way to represent the solubility-temperature relationship of several substances in a condensed format.

1.Which compound is the most soluble at 20 °C?

A.

B.

C.

D.

NR1.An equilibrium is established by adding 1200 g of to water to make a 1 L saturated solution at 10 ˚C. A quantity of solid remains at the bottom of the container. As the solution is heated, at what temperature will the system cease to be at equilibrium?

(Record your answer in the numeric response section on the answer sheet.)

______

2.What would you expect to occur when solid calcium sulfide, is added to a saturated solution of radium sulfide,

A.will precipitate.

B.will not dissolve.

C.No change in the concentration of

D.The value of for will decrease.

Use the following information to answer questions NR2 and 3.

Solubility charts, like the one shown, are a convenient way to represent the solubility-temperature relationship of several substances in a condensed format.

NR2.At what temperature is the solubility of and the same?

(Record your answer in the numeric response section on the answer sheet.)

3.Which of the following could form an equilibrium in 1 liter of water?

A.100 g of at 10 °C

B.300 g of at 70 °C

C.1000 g of at 50 °C

D.1000 g of at 50 °C

______

4.A saturated solution of barium carbonate () at 50 °C has a solubility of mol/L. The following equilibrium was established:

What is the value of the solubility product constant,

A.

B.

C.

D.

5.The following equilibrium was established for a saturated solution of silver chromate at 25 °C.

If the for is what is the chromate ion concentration in this solution?

A.

B.

C.

D.

6.Solutions of lead(II) nitrate and lithium bromide (LiBr) are mixed producing the following reaction:

After mixing, the concentration is mol/L and the concentration is mol/L. The of is

When comparing the trial calculated from this data with the known will a precipitate form?

A.The trial is larger than the given so no precipitate forms.

B.The trial is larger than the given so a precipitate does form.

C.The trial is smaller than the given so a precipitate does form.

D.The trial is smaller than the given so no precipitate forms.

6.CH30-EQ3 Observe and analyze phenomena related to acid-base reactions.

1.What is the conjugate base of

A.

B.

C.

D.

2.Which combination best describes a 0.1 M solution of HCl?

A.strong acid, dilute solution

B.strong acid, concentrated solution

C.weak acid, dilute solution

D.weak acid, concentrated solution

3.A 0.010 M solution of a weak acid, HA, has a hydrogen ion concentration of 0.001 0 M. The value for the acid is

A.

B.

C.

D.

4.If 0.225 mol of NaOH(s) are added to 1.0 L of water, what is the

A.

B.

C.

D.

5.What is the pH of a 0.01 mol/L solution of NaOH?

A.2

B.5

C.9

D.12

Use the pH Ranges of Common Indicators table supplied with this examination to answer the following question.

6.Indigo carmine works as an acid-base indicator (H-ind) and has the following equilibrium:

What color change would you expect to see when adding a base to a solution with a pH = 12.0 containing indigo carmine?

A.A green solution turns blue.

B.A yellow solution turns blue.

C.A green solution turns yellow.

D.A yellow solution turns green.

NR1.A student is performing a titration using hydrochloric acid and calcium hydroxide according to the following equation:

What volume (in mL) of 2.0 mol/L HCl is needed to neutralize 30.0 mL of

(Record your answer in the numeric response section on the answer sheet.)

7.Caustic soda solution, is very corrosive and must be handled with care. A caustic soda spill could be neutralized with acetic acid, according to the following reaction.

In the reaction, a Brønsted-Lowry conjugate acid-base pair is

A. and

B. and

C. and

D. and

8.Lactic acid is a weak acid which accumulates in muscle tissue when muscles are overexerted. Its presence leads to muscle pain and fatigue. The following equation shows the dissociation of lactic acid.

For the above dissociation, a 10.0 M solution of lactic acid has a mol/L. What is the value of for this dissociation?

A.

B.

C.

D.

9.The of a sample of soda water (carbonated water) is found to be What is the pH of the sample?

A.1.0

B.3.4

C.4.0

D.10.6

10.Three acid-base indicators were used to test an unknown solution. The following observations were made:

methyl red turns yellow

phenol red turns yellow

alizarin yellow turns yellow

Using the pH Range of Common Indicators table supplied with this examination, what is the approximate pH of this acid solution?

A.5.0–5.6

B.6.0–6.6

C.8.0–8.6

D.10.0–10.6

NR2.Boric acid, is used as a flame retardant. A student titrated this acid against 3.50 M LiOH. The following data were collected.

If the is 2.0 M, what is the final volume of ? (Round your answer to the nearest mL.)

(Record your answer in the numeric response section on the answer sheet.)

11.An indicator changes colour at a pH range of 8.4–10.2. Which combination below would be best suited for a titration using this indicator?

A. and

B.HBr and

C. and

D. and

7.CH30-EC1 Investigate the chemistry of oxidation and reduction (redox) reactions.

1.Which of the following synthesis reactions is NOT a redox reaction?

A.

B.

C.

D.

2.If fluorine is reduced during a reaction, what will happen to its number of electrons?

A.increases by one

B.decreases by one

C.increases by two

D.decreases by two

3.In the reaction what happens to the chlorine atom?

A.loses two electrons and is reduced

B.loses two electrons and is oxidized

C.gains two electrons and is reduced

D.gains two electrons and is oxidized

Use the following information to answer questions 4, 5, and 6.

4.In the above electrochemical cell, in which direction will the electricity flow?

A.from the silver solution through the salt bridge to the copper solution

B.from the copper solution through the salt bridge to the silver solution

C.from the copper electrode through the external circuit to the silver electrode

D.from the silver electrode through the external circuit to the copper electrode

5.What is the net ionic equation for the cell?

A.

B.

C.

D.

6.What is the function of the salt bridge in the electrochemical cell?

A.reduce the flow of electricity

B.maintain electrical neutrality within each beaker

C.provide electrons to balance the charge on the Ag strip

D.prevent the movement of ions from one beaker to the other

______

7.What is the oxidation number of the Cr atom in the ion?

A.+ 2

B.+ 3

C.+ 5

D.+ 6

8.The following reaction occurred when a strip of aluminum was placed in a nickel solution.

Which half reaction represents the oxidation that has occurred in the reaction?

A.

B.

C.

D.

NR1. Consider the following redox reaction.

When balanced, what are the lowest whole-number coefficients of and

(Record your answer in the numerical response section on the answer sheet.)

9.In an experiment, strips of metals X, Y, and Z were placed in 1.0 M solutions of and ions. The following results were observed:

The ions, listed in order of decreasing effectiveness in competition for electrons, are

A.

B.

C.

D.

Use the following information to answer questions 10, 11, and 12.

10.Which of the following statements about the cell is TRUE?

A.The silver electrode is the cathode.

B.Oxidation will occur at the silver electrode.

C.The positive ions in the solution will migrate toward the anode.

D.Electrons flow in the external circuit from the silver electrode to the aluminum electrode.

11.What is the net ionic equation for the reaction?

A.

B.

C.

D.

12.What is the voltage created by the electrochemical cell?

A.+ 0.74 V

B.+ 0.86 V

C.+ 2.46 V

D.+ 4.06 V

______

8.CH30-EC2 Examine applications of electrochemistry and their impact on society and the environment.

1.Which of the following metals could provide cathodic protection for Mn(s)?

A.Ni

B.Mg

C.Sn

D.Zn

Use the following information to answer questions 2 and 3.

Hydrogen fuel cells produce electricity by reacting hydrogen and oxygen gases. A diagram of the process is shown below.

2.According to the enclosed table of electrode potentials, what is the theoretical voltage created by the cell?

A.

B.

C.

D.

3.Certain metals can be fastened to the hull of an iron ship to give it cathodic protection in sea water. Which of the following metals would prevent the oxidation of Fe(s) to

A.Cu

B.Ni

C.Sn

D.Zn

4. Lead-acid batteries are commonly used as car batteries and account

for 40–45% of all batteries sold worldwide. The half reaction and

net ionic equation in the batteries are as follows:

Which of the following statements is true?

A.sulfur is oxidized

B.sulfur is reduced

C.lead is only oxidized

D.lead is oxidized and reduced

B.Released Questions (2016) – Chemistry 8256 Solution Pages

1.CH30-MS1 Examine the role of valence electrons in the formation of chemical bonds.

1. B.

Nitrogen is in group 15 and has 5 valence electrons.

1. C.

Magnesium is a metal and will lose electrons to a non-metal.

Magnesium is in group 2 and will lose both electrons to oxygen.

1. D.

Nitrogen as N3- has gained three electrons which, added to the original 5 electrons as a part of group 15, gives a total of 8.

1. A.
   

Nitrogen has a lone electron in NO2. As a molecule, there are:

Nitrogen – 5 electrons

Oxygen 6 – electrons each

Total electrons = 17. There must be a lone electron present.

1. A.

Selenium is in group 16 and has 6 valence electrons. It will gain 2 more

electrons to form an octet.

6.B

2.CH30-MS2 Investigate how the properties of materials are dependent on their underlying intermolecular and intramolecular forces.

1. A.

As an organic compound with a low boiling point, it has only dispersion

forces.

1. A.

Metallic bonding holds atoms of the same metallic element together. All

of the other choices are intermolecular forces between different elements

1. D.

CH3OH is an organic alcohol with weak hydrogen bonds – low boiling

point

3.CH30-MS3 Explore the nature and classification of organic compounds, and their uses in modern materials.

NR 1.16

C – C: 4 bonds

C – H: 12 bonds

Total = 16 bonds

1. A.

Determine the number of each element present for each compound:

i

ii

iii

iv

i and ii have the same number of each element so are isomers.

1. D.

5 carbon parent chain with a double bond on carbon 2: 2–pentene

2 - one carbon branches on carbons 2 and 3: 2,3–dimethyl

Name: 2,3–dimethyl–2–pentene

1. A.

An alcohol contains C–OH

1. A.

6 carbon parent chain with a triple bond: hexyne

Number from the right for a smaller number for the triple bond: 2–

Name: 2–hexyne

NR 2.14

1. C.