Name: ______Date: ______

Chemistry 30S Exam Review

Unit 1: Physical Properties of Matter

  1. List the statements that make up the Kinetic Molecular Theory.

All matter is made up of small particles that are in continuous, random, straight-line motion.

All collisions are perfectly elastic.

The average speed of the particles determines the average temperature.

As Kinetic energy goes up, so does the speed of the particles and the number of collisions.

  1. Describe the shape and volume associated with each of the states of matter.

Solids – Definite shape and has its own volume.

Liquids – Takes the shape of its container and has its own volume

Gas – Takes the shape and volume of its container

Plasma - Takes the shape and volume of its container

  1. Describe each of the states of matter according to their compressibility, density, and ability to diffuse.

Solids –no to very low compressibility, high density, no diffusion

Liquids – low compressibility, moderate density, low to moderate diffusion

Gases – high compressibility, low density, high diffusion

  1. Why do gases diffuse easily, but solids do not?

The bonds holding gases together are nonexistent or very weak. The bonds holding a solid together are strong.

  1. Using the graph to the right identify the following points:
  2. Solid – A-B
  3. Liquid – C-D
  4. Gas – E-F
  5. Melting point – B-C 15°C Stable temperature means bonds are breaking (heat is being used to break bonds)
  6. Freezing point – C-B 15°C

Although heat is being removed, the temperature is stable because creating bonds gives off energy (replacing the heat that is removed)

  1. Boiling point – D-E 95°C
  2. Condensation point – E-D 95°C
  1. Which of the four processes in d-g in the question above require energy, release energy, and undergo a temperature change during the process?

d. breaking bonds so using energy, no temperature change – molecules stay the same speed

e. making bonds so releasing energy, no temperature change

f. breaking bonds so using energy, no temperature change

g. making bonds so releasing energy, no temperature change

  1. Describe what is happening to the temperature, kinetic energy, molecular movement, and IMFs while a solid is melting to a liquid. Begin in the solid phase and end in the liquid phase.

As a solid is heated the temperature goes up and the KE increases and therefore, molecular speed increases. Nothing is happening with the bonds.

During melting, temperature stays the same, so KE and speed stay the same. Bonds are breaking.

Once the liquid is completely formed and is heated, temperature goes up, and KE and molecular speed go up. Nothing is happening with the bonds.

  1. Define the following terms:

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. Freezing – when a liquid changes to a solid, temperature remains constant and bonds are created
  2. Condensation – when a gas changes to a liquid, temperature remains constant and bonds are created
  3. Evaporation – when a liquid changes into a gas, temp remains constant and bonds are breaking
  4. Boiling point – the temperature at which the vapour pressure of a liquid equals the atmospheric pressure
  5. Sublimation – when a solid changes into a gas, temp remains constant and bonds are broken
  6. Deposition – when a gas changes into a solid, temp remains constant and bonds are created

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. Explain on the molecular level how condensation occurs. Include kinetic energy, molecular movement, and IMFs in your answer.

1)Collision – Molecules collide (gas molecule hits a solid container/liquid)

2)Energy transfer – Gas molecule will transfer energy (lose energy) to the solid or liquid

3)Bonds – Gas molecule no longer has energy to exist as a gas and will form bonds (with liquid molecules) to become a liquid

  1. What occurs during dynamic equilibrium? What conditions must exist for it to occur?

Dynamic Equilibrium is when two opposite process occur at the same rate.

Closed container. Need to opposite processes (evaporation and condensation, freezing and melting)

  1. What two things does the vapour pressure of a pure liquid depend on?

Bond strength (nature of liquid) and temperature

  1. Using the diagram below identify the normal boiling points of the three liquids.

Ether – 308K

Ethanol – 350K

Water – 373K

Unit 2: Gases

  1. What does Boyle’s Law state? Is this a directly or indirectly proportional relationship?

Pressure and volume are indirectly proportional. i.e., As the pressure of a gas goes up, the volume of the gas goes down.

Indirectly proportional.

  1. What is Charles’ Law? Is this a directly or indirectly proportional relationship?
    Volume and temperature are directly proportional. i.e., As the temperature of a gas goes up, the volume of a gas goes up.

Directly proportional

  1. What is Gay-Lussac’s Law? Is this a directly or indirectly proportional relationship?

Pressure and temperature are directly proportional. i.e., As the temperature of a gas goes up, the pressure of a gas goes up.

Directly proportional

  1. If a flexible container holds 4.50L of a gas at 2.04 atm, what is the new pressure when the volume increases to 6.50L? (1.41atm)

P1V1 = P2V2

  1. What is the new volume of a gas that begins at 230mL and is then heated from 23.0°C to 54.0°C? (254mL or 0.254L)

V1T2 = V2T1

  1. What is the new pressure of a gas that is cooled from 65.0°C to -5.00°C? The original pressure was 96.0kPa. (76.1kPa)

P1T2 = P2T1

  1. What does adding more molecules of gas do to the volume and/or pressure of the gas?

It increases the volume if it is added to an expandable container. It increases the pressure if it is in a rigid container.

  1. Explain on the molecular level why:
  2. The pressure of a gas inside a container increases when it is heated

Molecules gain kinetic energy and move faster. This means they collide with the sides of the container more often and this exerts more pressure.

  1. The pressure of a gas decreases when the volume of the container it is in increases?

As the volume increases, the molecules have more space to move around. This means they hit the sides of the container less often and this exerts less pressure.

  1. Be able to draw or identify each of the three gas laws in their graph formats.

CharlesBoyles Guy-Lussac

Unit 3: Basic Skills

  1. What is the atomic mass of the element Chlorine if it is made up of the following isotopes: 35Cl = 75.8% and 37Cl = 24.2%? (35.48amu)
  1. Write out the names of the following formulas:

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. Cu2SO3 – Copper (I) sulphite
  2. NH4ClO4 – Ammonium perchlorate
  3. Na2CrO4 – Sodium chromate
  4. CaSO4 – Calcium sulphate
  5. Mg(BrO3)2 – magnesium bromate

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. Write out the formulas for the following names:

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. Lithium chlorate – LiClO3
  2. Barium phosphate – Ba3(PO4)2
  3. Manganese (IV) nitrite - Mn(NO3)4
  4. Potassium carbonate – K2CO3
  5. Aluminum chlorite – Al(ClO2)3

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. In your notes find examples of the five types of reactions: combustion, synthesis, single displacement, double displacement, and decomposition.

Synthesis: Mg + O2 → MgO

Decomposition: K2O → K + O2

Single Displacement: Li + CaS →Li2S + Ca

Double Displacement: Pb(NO3)2 + KI → KNO3 + PbI2

Combustion: C6H12O6 + O2 → CO2 + H2O

  1. Balance the following reactions:
  2. 2KClO3 → 2KCl + 3O2
  3. H2SO4 + 2NaOH → Na2SO4 + 2H2O
  4. 2Fe(NO3)3 + 3(NH4)2CO3→ Fe2(CO3)3 + 6NH4NO3
  5. Cu3(PO4)2 + 3Na2SO4→3CuSO4 + 2Na3PO4
  6. AlCl3 + 3H2O → Al(OH)3 + 3HCl
  1. Predict the products of the following reactions.

Synthesis:

  1. K + O2→ K2O b. Mg + S8→ MgS

Decomposition

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

a.NaCl→ Na + Cl2

b.CaF2→ Ca + F2

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

Double Displacement:

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. BaCl2 + NaF→ BaF2 + NaCl
  2. Pb(NO3)2 + KI→ PbI2 + KNO3

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

Single Displacement

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. CaBr2 + F2→ CaF2 + Br2
  2. Li + Al(OH)3→ LiOH + Al

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

Combustion

a. CH4 with sufficient oxygenCH4 + O2 → CO2 + H2O

b. C2H6 with insufficient oxygenC2H6 + O2 → CO + H2O

  1. Translate the following word equations into chemical equations and balance them.
  2. Copper and solid zinc oxide react in a single displacement reaction to make a solid green compound and a new metal.

Cu + ZnO → CuO + Zn

  1. Solid calcium nitride and fluorine gas react to form a new solid compound and an inert gas.

Ca3N2(s) + 3F2(g) → 3CaF2 + N2(g)

  1. Aqueous potassium hydroxide and dissolved hydrofluoric acid (HF) react to form water and a dissolved salt.

KOH(aq) + HF(aq) → H2O(l) + KF(aq)

  1. Lithium metal and water react to make a dissolved compound and a gas.

3Li(s) + H2O(l) → Li2O(aq) + H2(g)

  1. Dinitrogen pentoxide gas breaks down into two elemental gases.

2N2O5(g) → 2N2(g) + 5O2(g)

  1. Magnesium when burned in air forms a solid white compound.

2Mg(s) + O2(g) → 2MgO

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

Unit 4: The Mole and Chemistry

  1. Calculate the molecular (molar) mass of Nitrogen dioxide.(46.005g/mol)
  1. What mass of sodium do I have if I have 5.67 moles of the element?(130g)
  1. What volume will 1.2 moles occupy at STP? (27L)
  1. What is the mass of 4.52 x 1024 atoms of Boron?(81.1g)
  1. How many atoms of chromium are there in 1 molecule of Al2(Cr2O7)3?(6 atoms)
  1. What is the molar mass of a gas if I have 0.854g of the gas in a 1.56L container at a pressure of 0.987atm and a temperature of 27.0⁰C? (13.7 g/mol)
  1. What mass of Fluorine gas occupies 2.0L at 25°C and 104.0kPa? (3.2g)
  1. What pressure will 1.50 moles of Ammonia gas (NH3) exert when placed in a 4.5L container at 18°C? (8.0atm or 807kPa)
  1. What volume does 56.7g of chlorine gas occupy at 32°C and 1.2atm? (16.4L)
  1. What is the density of sulphur dioxide at 34°C and 1.2 atm? (3.05g/L)
  1. What is the molar mass of a gas that has a density of 35.6 g/L at 12°C and 115kPa? (734g/mol)
  1. Solve the following stoichiometric questions below using following reaction:

2 Cu2S(s) + 3O2(g)→ 2Cu2O(s) + 2SO2(g)

  1. If I have 4.5 moles of oxygen gas, how many moles of sulphur dioxide can I make?(3 moles SO2)
  1. What mass of copper (I) oxide can be made from 5.6g of copper (I) sulphide?(5.0g)
  1. What mass of copper (I) oxide are produced from 4.5L of oxygen gas at STP?(19.2g)
  1. What volume of Sulphur dioxide can be made from 8.65g of copper (I) sulphide at 23°C and 102.3 kPa?(1.3L)
  1. What mass of copper (I) oxide can be made from 5.6g of copper (I) sulphide and 6.0L of oxygen gas and 24°C and 0.92 atm?(5.0g)
  1. To calculate limiting reactant questions which of the following do you need?

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. A balanced reaction
  2. The mass of one reactant
  3. The mass of both reactants
  4. The mass of the products

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Chemistry 30S– Exam Review January 2015

Name: ______Date: ______

  1. Calculate the percent composition of each element in potassium phosphide.(K = 79.1%; P = 20.9%)
  1. What is the difference between a structural formula, an empirical formula and a molecular formula?

A structural formula gives the position of the atoms and their bonds in a diagram.

An empirical formulas gives the formula in the lowest possible ratio, CH3

A molecular formula gives the formula with all the atoms present, C2H6

  1. A certain compound was found to be made up of 61.5% Mercury and 38.5% Iodine. Its molecular mass was determined to be 656 g/mol.
  2. What is the empirical formula for this compound?(HgI)
  3. What is the molecular formula for this compound?(Hg2I2)

Unit 5: Solutions

  1. What does dissociation mean? What about solvation/dissolution?

Dissociation is the breaking apart of a solid in water.

Solvation/Dissolution is the surrounding of ions or molecules by the water molecule to dissolve a solute.

  1. Explain the difference between the dissolution of an ionic compound and the dissolution of a molecular compound.

An ionic compound breaks apart into ions and water surrounds the ions in specific ways, positive ion to oxygen, and negative ion to hydrogen

A molecular compound breaks apart into molecules and water can surround the molecule with both the hydrogen and oxygen end.

  1. Write out the dissolution equations for:
  2. Ba3(PO4)2→3Ba2+(aq) + 2PO4-3(aq)
  3. C2H4→ C2H4(aq)
  1. Describe the structure of water in terms of electronegativity and polarity.

Water has a distinct positive and negative end. The hydrogen end is positive because hydrogen is less electronegative than oxygen so the electron spends less time around the hydrogen in the O-H bond. The oxygen atom is negative because it is more electronegative than hydrogen so that the electrons spend a lot of time around it in the O-H bond.

Electronegative – the ability to attract an electron when bonded to another atom.

  1. Explain, on the molecular level, why polar and nonpolar substances do not dissolve each other.

Polar substances are attracted to each other by their positive and negative ends. Nonpolar substances do not have positive and negative ends, so they will not be attracted to nonpolar substances. Therefore polar substances will collect together and nonpolar substances will collect with each other.

  1. What is the difference between an exothermic and an endothermic reaction?

An exothermic reaction is one in which heat exits the reaction/system. e.g. freezing

An endothermic reaction is one in which heat enters the reaction/system. e.g.melting

  1. Explain, on the molecular level, how a dissolving a solute can be an exothermic process.

When solute-solute bonds break and solvent-solvent bonds break, this requires energy (endothermic). When solute-solvent bonds form, this gives off energy. When more energy is given off than is taken in, you have an exothermic dissolving process.

  1. Explain, on the molecular level, how a dissolving a solute can be an endothermic process.

When solute-solute bonds break and solvent-solvent bonds break, this requires energy (endothermic). When solute-solvent bonds form, this gives off energy. When more energy is taken in than is given off, you have an endothermic dissolving process.

  1. What happens to the solubility of a gas when the solution is heated? Why? When pressure on the solution increases? Why?

The gas becomes less soluble when the solution is heated because gas molecules in the liquid move faster and this causes the gas bubbles to expand. When the bubbles are large enough and sufficiently low enough in density, they rise to the surface and out of the liquid.

When pressure is increased, the solubility of a gas increases. Gas molecules above the solution have less space to move and so they hit the solution more often and will dissolve more often into the solution.

  1. What happens to the solubility of a solid when the solution is heated? Why? When pressure increases?

The solid will increase in solubility because when the solution is heated solvent molecules increase in speed and will hit the solute more frequently pulling more solute into the solution.

Changing pressure does not affect the solubility of a solid.

  1. A 3.4M solution of Cu2SO4 is made. What are the Cu+1 ion and SO4-2 ion concentrations?([Cu+1] = 6.8M; [SO4-2 = 3.4M])

Cu2SO4 → 2Cu+ + SO42-

Since there are twice as many Cu ions as there is salt, the concentration of Cu ion will be double. Since there are as many sulphate ions as salt, the concentration of sulphate ion will be the same as the salt concentration.

  1. What mass of Al(OH)3 is need to create 55.4mL of a 0.855M solution?(22.3g)

n = C/V; once you have the moles, change the moles to grams using the molar mass of Al(OH)3

  1. What is the concentration of a solution that contains 4.50g of lead (IV) iodide in 550mL of solution?(0.011M)

Change grams to moles using the molar mass of PbI4, then use C=n/V to find concentration. Don't forget to change mL to L by dividing by 1000.

  1. What is the new volume if 255mL of 1.2M hydrochloric acid (HCl) is diluted to 0.2M?(1.53L)

C1V1 = C2V2

  1. Define the words below and then identify the regions on the solubility chart where they occur.
  2. Saturated - a solution that contains the maximum amount of dissolved salt, found on the line
  3. Supersaturated - a solution that contains the more than the maximum amount of dissolved salt, found above the line
  4. Unsaturated - a solution that contains the less than the maximum amount of dissolved salt, found below the line
  1. Use the solubility table to answer the following questions:
  2. A solution of KNO3 was created by adding 39g of the salt to 60g of water at 70.0°C.
  3. Is the solution saturated?

(39g/60g) = (Xg/100g) X = 65g It is unsaturated.

  1. If not how much of the salt must be added to saturate the solution?(42g)

135g - 64g = 70g/100g H2O

(70g/100g) = (Xg/60g) X = 42g

  1. To what temperature must the solution be cooled to create a saturated solution?

42°C

  1. Identify what adding a solute to a pure solvent does to the
  2. Vapour pressure of the solution - lowers it
  3. Boiling point of a solution - raises it
  4. Freezing point of a solution - lowers it
  1. Explain, on the molecular level, why you see a decrease in the freezing point of a solution when the solute is added.

The solute molecules get in the way of the crystal structure forming. This means more heat needs to be removed to have the solid crystal structure form as the freezing point is lowered.

  1. Explain, on the molecular level, why you see a rise in the boiling point of a solution when a solute is added.

The solute molecules at the surface of the solution prevent the solvent from becoming vapour. This lowers the vapour pressure of the solution. Since boiling requires the vapour pressure of the solvent to equal the atmospheric pressure, more heat needs to be added to create the vapour pressure needed to achieve boiling.

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Chemistry 30S– Exam Review January 2015