chemistry 2nd semester - rozema's...

CHEMISTRY 2ND SEMESTER FINAL EXAM PRACTICE TEST

*These are OLD TESTS. Your Final Exam will have questions VERY SIMILAR to your old tests! *

UNIT 7-GAS LAWS_____1. Which of the following statements best describes the movement of molecules in gases?A) Molecules do not move at all and stay fixed in space.B) Molecules vibrate back and forth, staying together as if they were connected by a spring.C) Molecules are free to move around each other in all directions, but still stay close together.D) Molecules are free to move around in all directions and are not close together or held together by forces of attraction.

2. When a sample of gas is heated, its kinetic energy(A) increases (B) decreases(C) remains the same (D) varies depending on the pressure(E) varies depending on the volume

3. The pressure exerted by a gas in a container depends on

(A) the space between the molecules(B) the instrument used to measure the pressure

(C) the number of collisions between gas molecules and other gas molecules(D) the number of collisions between gas molecules and the walls of the container

_____4. How does increasing the temperature of a gas at constant volume cause an increase in pressure? A) The number of particles inside the container increases.B) The particles move at the same speed but hit the walls of the container more frequently.C) The particles move faster and hit the walls of the container with more force.D) The particles expand and hit the walls of the container with more force.

100 mL @ 20C

For questions 5-7, the diamond shape () on the graph is represented by the designated picture below. Identify the picture that best represents point on the graph marked with an arrow.

8. The diagram below left shows a representation of a 100 mL sample of gas at 20˚C. Which picture best illustrates the new volume of the gas at 0˚C? Hint: first calculate the new volume and the select the picture that best illustrates the new volume.

9. Assuming that the pressure of a gas and the number of particles stays constant, what happens to the volume when the temperature is decreased?

(A) It increases (B) It decreases(C) It remains the same (D) It varies inversely

10. Which of the following is NOT a unit of pressure?(A) mmHg (B) mL (C) atm(D) psi (E) kPa

= P

V

5. ____

P

T

6. ____

P

n

7. ____

A B C D E F

_____11. What happens to the volume and density (how closely the molecules are packed) of a gas as the gas is heated in a flexible container?

(A) Both volume and density increase.(B) Volume decreases and density increases.(C) Volume increases and density decreases.(D) Both volume and density decrease.

____12. Refer to the picture in Question #5. At the point designated by the arrow, which of these conditions is most accurate?(A) High pressure, low volume (B) High pressure, high volume (C) Low pressure, low volume (D) Low pressure, high volume

_____13. Which event is a hypothetical occurrence at the temperature 0 K? (A) Solid materials contract to zero volume.(B) All motion of atoms and molecules stops.(C) Water changes from liquid to solid.(D) Carbon dioxide changes from gas to solid.

____14. At 1 atm of pressure, the volume of a balloon is 3.4 L. Assuming that the temperature remains constant, what will the volume of the balloon be at 0.6 atm of pressure? (space is provided to do a calculation if needed)(A) 0.18 L (B) 2.04 L (C) 3.4 L (D) 4.0 L (E) 5.67 L

____15. A gas in a closed, steel tank at 50ºC has a pressure of 2.00 atm. If the temperature of the gas is decreased to 25ºC, what is the new pressure of the gas? (space is provided to do a calculation if needed)(A) 1.00 atm (B) 1.85 atm (C) 2.00 atm (D) 2.17 atm (E) 4.00 atm

____16. A gas in a closed syringe has a temperature of 25ºC, a volume of 50 mL, and pressure of 1 atm. The volume is decreased and the temperature is changed increased. What is the result?

(A) The resulting pressure must decrease(B) The resulting pressure must increase(C) The resulting pressure remains the same(D) It is impossible to determine the resulting pressure without knowing the values of the new volume and

temperature.

____17. Which statement best describes the difference between the atmosphere at sea level and the atmosphere at the top of a tall mountain?

A) More molecules are in a given volume of air at sea level and they exert greater pressure.B) The number of molecules in a given volume is the same but they move faster at sea level.C) The number of molecules in a given volume is the same but they move slower at sea level.D) Fewer molecules are in a given volume at sea level but they are under greater pressure.

18. The gas in the box at left has a higher pressure than the gas in the box at the right. Draw “whooshies” on the particles in each box to represent their relative motion. (2 pts)

a)

_____b) Why is the pressure is higher in the box on the left on the particle level? A) The temperature in the box on the left is lower causing fewer collisions.B) The temperature in the box on the left is higher causing fewer collisions.C) The temperature in the box on the left is lower causing more collisions.D) The temperature in the box on the left is higher causing more collisions.

_____19. If the number of particles in the left box above were doubled, what would happen to the pressure of the gas? A) The pressure is cut in half.B) The pressure remains the same.C) The pressure is doubled.D) The pressure is multiplied by four.

20. Use the factor label method (dimensional analysis) to convert 82 psi to mmHg. Use the conversion factor 760 mmHg = 14.7 psi (2 pts for setup, all or nothing, 2 pts for answer)

21. Below are three particle representations of the pressure and volume relationship. Assume that the length of the whooshies are the same.

a) Which box has the highest pressure? ______ (1 pt)b) Which box has the lowest pressure? ______ (1 pt)

1 2 3c) What variable(s) is/are held constant in these three pictures? How can you tell from the drawings that these things are held constant? (2 pts)

22. A gas in closed piston has a temperature of 450ºC, a volume of 100 mL, and constant pressure of 2.0 atm. The temperature is decreased to 25ºC and the pressure is held constant. What is the final volume? T(K) = C + 273a. Circle and list the knowns, underline and list unknowns. Show all units. (1 pt)

b. What is/are held constant or assumed to be held constant? (1 pt) ___________________

c. Cause and effect? (You must use the word “so”) (2 pts) ________________________

d. Do the calculations. (2 pts for the setup, 2 pts for the answer) WRITE DOWN ALL UNITS!

23. A gas in syringe has a constant temperature of 25C, an initial volume of 20 mL, and pressure of 740 mmHg. The volume is increased to 58 mL. What is the new pressure in the syringe? a. List the knowns and unknowns. Show all units. (1 pt)

b. What is/are held constant or assumed to be held constant? (1 pt) ___________________

c. Cause and effect? (You must use the word “so”) (2 pts) ________________________

d. Do the calculations. (2 pts for the setup, 2 pts for the answer) WRITE DOWN ALL UNITS!

UNIT 8-REACTIONS

_____ 1. If you saw the following chemical reaction take place, what would you see?Na2CO3 (aq) + 2C2H4O2 (aq) 2NaC2H3O2 (aq) + H2O (l) + CO2 (g)

(A) solid forming in a liquid (B) a solid dissolving in a liquid(C) only a clear liquid (D) bubbles forming in the mixture

_____ 2. If you saw the following chemical reaction take place, what would you see? 2KOH (aq) + CuCl2 (aq) 2KCl (aq) + Cu(OH)2 (s)

(A) just a clear liquid (B) just a solid (C) bubbles forming in a liquid (D) nothing(E) solid forming in a liquid

_____ 3. Which of the following chemical equations properly describes this verbal description of a reaction:“Solid calcium oxide reacts with water to form solid calcium hydroxide, which is only slightly soluble in water.”(A) 2CH4O(l) + O2(g) 2CH2O(l) + 2H2O(l)(B) H2SO4(aq) + CaCO3(s) CaSO4(aq) + CO2(g) + H2O(l)(C) CaO(s) + H2O(l) Ca(OH)2(s) (D) 2C8H14(l) + 23O2(g) 16CO2(g) + 14H2O(l)

_____ 4. CO2 (s) CO2 (g) is an example of (A) a chemical change (B) a physical change (C) a decomposition reaction (D) a combination reaction(E) both A and C

_____ 5. Which of the following chemical equations would be considered a physical change? (A) NaCl (aq) + AgNO3 (aq) NaNO3 (aq) + AgCl (s)(B) CO2 (s) + H2O (l) H2CO3 (aq)(C) CO2 (s) + Ca(OH)2 (aq) CaCO3 (s) + H2O (l)(D) C2H6O (l) C2H6O (g)(E) CaCl2 (aq) + 2NaOH (aq) Ca(OH)2 (s) + 2NaCl (aq)

____ 6. What is the correct description of this reaction?Mg (s) + H2SO4 (aq) MgSO4 (aq) + H2 (g)

(A)Solid magnesium reacts with a solution of sulfuric acid to produce a solution of magnesium sulfate and hydrogen gas.

(B) Hydrogen gas reacts with a solution of magnesium sulfate to produce solid magnesium metal in a solution of sulfuric acid.

(C) Hydrogen gas reacts with solid magnesium to produce solid magnesium sulfate in a solution of sulfuric acid.(D)A solution of magnesium sulfate reacts with a solution of sulfuric acid to produce solid magnesium and

hydrogen gas.

7. Water is added to solid calcium chloride to produce aqueous calcium chloride. Will the weight change when the solid dissolves? (Circle >, =, or <.)

CaCl2 (s) CaCl2 (aq)

8. Aqueous sodium carbonate is added to aqueous nitric acid to produce aqueous sodium nitrate, water, and carbon dioxide gas. Will the weight change when the two reactants are combined? (Circle >, =, or <.)

Na2CO3 (aq) + 2 HNO3 (aq) 2 NaNO3 (aq) + H2O (l) + CO2(g)

9. Aqueous silver carbonate is added to aqueous sodium chloride to produce aqueous sodium nitrate and solid silver chloride. Will the weight change when the two solutions combine? (Circle >, =, or <.)

AgNO3 (aq) + NaCl (aq) NaNO3 (aq) + AgCl (s)

_____ 10. Does the following chemical equation demonstrate the law of conservation of mass? CH4(g) + 2O2(g) CO2(g) + 2H2O(l)

(A) Yes, because there are the same number of molecules of reactants & products. (B) Yes, because there are the same number of atoms of each element in reactants and products. (C) No, because one of the products is a liquid, not a gas.(D) No, because there are different compounds on the two sides of the arrow.

_____ 11. New substances formed in a chemical reaction are called(A)coefficients (B) products(C) subscripts (D) reactants

_____ 12. Numbers placed in front of formulas in an equation are called(A)coefficients (B) products(C) subscripts (D) reactants

_____ 13. Which of the following is always equal on each side of the arrow in a balanced chemical reaction?

? g

> = <

? g Reactants Products

> = <

? g


? g

> = <


(A) Total number of atoms (B) Total number of molecules(C) Sum of the coefficients (D) Sum of the subscripts

_____ 14. What type of reaction is this? AgNO3 (aq) + KCl (aq) AgCl (s) + KNO3 (aq)(A) single exchange (B) double exchange (C) combination (D) decomposition

_____ 15. What type of reaction is this?2Mg (s) + O2 (g) 2MgO (s)(A) single exchange (B) double exchange (C) combination (D) decomposition

_____ 16. What type of reaction is this? Zn (s) + 2HCl (aq) ZnCl2 (aq) + H2 (g)(A) single exchange (B) double exchange (C) combination (D) decomposition

_____ 17. Which of the following is one of the correct products of the following double exchange reaction:NaOH + HCl ____ + ____ ? (A) NaH (B) ClOH (C) NaCl (D) NaO (E) H2

18. What should be the total number of C atoms on the left side of the equation? (2 points)

Answer: _________

19. What is the formula of the missing reactant molecule? (2 points)

Answer: ______________

20. Write the completed chemical equation for the reaction pictured.

_________________________________________

+

O

OO

OO

O

CO

O

CO

O

H HO

H HO

+?

Balance the following reactions. (use scratch paper if necessary)

21. ____Ca + ____O2 ____CaO

22. ____Al + ____HCl ____AlCl3 + ____H2

23. ____C3H8 + ____O2 ____CO2 + ____H2O

24. ____Sr(OH)2 + ____FeCl3 ____SrCl2 + ____Fe(OH)3

Write balanced equations for each of the following chemical reaction.

25. Solid iron burns in air to form a black solid, iron(III) oxide, Fe2O3.

26. Chlorine gas and water vapor react to produce hydrogen chloride gas and oxygen gas.

Unit 9-Moles ______1. Which of the following is NOT true about one mole?

(A) one mole contains 6.02 x 1023 particles(B) 12.01 g of carbon equals one mole of carbon atoms(C) the mass of 1 mole of carbon atoms = the mass of 1 mole of boron atoms(D) the number of atoms in 1 mole of carbon = the number of atoms in 1 mole of boron

______2. The number of oxygen atoms represented by the formula Pb(C2O4)2 is(A) 10 (B) 8 (C) 6 (D) 4 (E) 2

______3. The total number of atoms in one molecule of Pb(C2O4)2 is(A) 14 (B) 13 (C) 9 (D) 8 (E) 3

______ 4. One mole of basketballs = _______________________(A) 6.02 x 1023 basketballs (B) 6.02 basketballs(C) 10.23 x 106.02 basketballs (D) 6.02 x 10 basketballs(E) 1 x 1023 basketballs

______ 5. 24.08 x 1023 porcupines = _______________________(A) 1 mole of porcupines (B) 2 moles of porcupines(C) 3 moles of porcupines (D) 4 moles of porcupines

______ 6. How many atoms of hydrogen are there in 1.0 moles of hydrogen, H2? Work space is given below if needed.(A) 6.02 x 1023 molecules (B) 12.04 x 1023 molecules(C) 18.06 x 1023 molecules (D) 24.08 x 1023 molecules(E) 36.12 x 1023 molecules

______ 8. How many total atoms are there in 1.0 moles of hydrogen, H2? Work space is given below if needed.(A) 6.02 x 1023 total atoms (B) 12.04 x 1023 total atoms(C) 18.06 x 1023 total atoms (D) 24.08 x 1023 total atoms(E) 36.12 x 1023 total atoms

11.

a) ________ moles of N2 = __________ moles of NH3

b) ________ moles of H2 = __________ moles of NH3

c) ________ moles of N2 = __________ moles of H2

12. 1 Cu (s) + 2 AgNO3 (aq) 2 Ag (s) + 1 Cu(NO3)2 (aq)

a) ________ moles of AgNO3 = __________ moles of Cu(NO3)2

b) If we had 10 moles of AgNO3, how many moles of Cu(NO3)2 would we have? ____________

---------------------------------------------------------------------------------------------------------------------------------------

After

The above pictures represent this chemical reaction: 2 S + 3 O2 2 SO3

13. What is the limiting reactant? ______________________________

14. There is a nickel (Ni) coin that weighs 1.86 g. How many moles of nickel are there? (4 pts.)

1 N2 + 3 H2 2 NH3

Before

a. 1 mole of Ni = ___________________ g

b. Solve this Problem:

c. Your final answer is ___________________

15. A student needs to use 0.56 moles of lithium bromide, LiBr, in an experiment. How many grams will he need? (4 pts.)

a. 1 mole of LiBr = ___________________ g



16. How many grams are there in 0.68 moles of Mg(OH)2? (4 pts.)

a. 1 mole of Mg(OH)2 = ___________________ g



Unit 10-ACIDS & BASES

Part 1: Molar Concentration

_____ 1. If you have 6 mol of glucose in 3 L of solution, what is the molarity of the solution? Space is given to do a calculation if necessary.

(A) 0.5 M (B) 2.0 M (C) 3.0 M (D) 9.0 M (E) 18.0 M

_____ 2. What is the molarity of a solution containing 15 g of NaCl in 500 mL of solution? Space is given to do a calculation.

(A) 1.75 M (B) 0.51 M (C) 30 M (D) 7.5 M (E) 0.03 M

3. A 22.4 g sample of sodium chromate, Na2CrO4, is dissolved in enough water to make a 635 mL of solution. Determine the molar concentration of the sodium chromate. SHOW ALL UNITS!

a) What is the Molar Mass of Na2CrO4 ?

b) Convert grams to moles:

c) Convert mL to L: (1 L = 1000 mL)

d) Calculate the molar concentration of Na2CrO4:

Figure 1 represents a 1.0 L solution of sugar dissolved in water. The dots in the magnification circle represent the sugar molecules. In order to simplify the diagram, the water molecules have not been

shown.

_____ 6. Which response represents the view after 1.0 L of water was added (Figure 2)? Hint: Be sure to count the number of dots in each answer.

Part 2: Acids and Bases

_____ 7. If a solution has a pH of 7, it is…(A) an acid (B) a base (C) neutral (D) an indicator

_____ 8. If a solution has a pH of 3, it is…(A) an acid (B) a base (C) neutral (D) an indicator

_____ 9. To dilute an acid, you would use…(A) a base (B) an acid (C) water (D) an indicator (E) a salt

_____ 10. You test an unknown solution with universal indicator. The indicator stays green (neutral pH). The unknown solution is most likely:

(A) lemon juice; citric acid, C6H8O7 (B) ammonium hydroxide, NH4OH(C) drain cleaner; sodium hydroxide, NaOH (D) table salt; sodium chloride, NaCl(E) stomach acid; hydrochloric acid, HCl

_____ 11. You test an unknown solution with calcium carbonate, CaCO3. The solution forms bubbles. The unknown solution is most likely:

(A) drain cleaner; sodium hydroxide, NaOH (B) rubbing alcohol, C3H8O(C) vinegar, acetic acid, C6H8O7 (D) table salt; sodium chloride, NaCl(E) washing soda, sodium carbonate, Na2CO3

_____ 12. You test an unknown solution with universal indicator. It has a pH of 10. The unknown solution is most likely:

(A) window cleaner; ammonium hydroxide, NH4OH (B) table salt; sodium chloride, NaCl(C) water, H2O (D) vinegar; acetic acid, C2H4O2

(E) stomach acid; hydrochloric acid, HCl

UNIT 11-FIREEquations: heat = m•C•∆T heat = (mass)•(specific heat capacity)•(Tf-Ti)Multiple Choice (3.4 pts each)

_____ 1. You take a teaspoon of ammonium chloride, NH4Cl, and put it in some water that starts at 25ºC. After mixing in the NH4Cl, the temperature changes to 5ºC. What is the value of ∆T?

(A) –20ºC (B) +20ºC (C) +25ºC (D) +5ºC (E) +125ºC

(A) (B) (C) (D) (E)

_____ 2. Which of these conditions is always true for an endothermic process?(A) The temperature increases during the process.(B) Energy is transferred from the surroundings to the system. (C) A chemical reaction occurs.(D) The solution feels hot.(E) Molecules move more quickly at the end of the process.

_____ 3. When two or more objects in contact with one another reach the same temperature, it is called(A) endothermic (B) exothermic

(C) thermal equilibrium (D) kinetic energy

_____ 4. You have water at 25ºC. You dissolve calcium chloride, CaCl2, in the water and the temperature increases to 45ºC. Which of the following statements is/are true?

I The process is endothermic.II. The process is exothermic.III. Energy is transferred from the system to the environment. IV. Energy is transferred from the environment to the system.

(A) I and III only (B) II and III only(C) I and IV only (D) II and IV only

_____ 5. When an ice cube tray filled with water is put into a freezer,(A) cold is being transferred into the water(B) cold is being transferred out of the water(C) heat is being transferred into the water(D) heat is being transferred out of the water (E) the temperature of the water stays constant

_____ 6. You place your hand into a bucket of hot water for 30 seconds. After drying your hand, you quickly place it into a bucket of lukewarm water. What should your hand feel like and why?

(A) It feels cold because heat is being transferred from your hand to the lukewarm water.(B) It feels cold because heat is being transferred from the lukewarm water to your hand.(C) It feels cold because cold is being transferred from the lukewarm water to your hand. (D) It feels warm because heat is being transferred from your hand to the lukewarm water.(E) It feels warm because heat is being transferred from the lukewarm water to your hand.____ 7. Why does your skin feel cool when rubbing alcohol evaporates from your skin?

(A) Heat is being transferred from your hand to the alcohol. (B) Heat is being transferred from the alcohol to your hand.(C) Cold is being transferred from the alcohol to your hand. (D) Cold is being transferred from your hand to the alcohol.

_____ 8. Choose the best definition of temperature.(A) Temperature is a measurement of how much heat something has. (B) Temperature is a measurement of the hotness or coldness of an object.(C) Temperature is a measurement of the total energy of a bunch of particles. (D) Temperature is a measurement of the average kinetic energy of a bunch of particles.(E) Temperature is a measurement of the force caused by molecules striking the walls of a container.

_____ 9. The temperature of a substance is related to:(A) Only the speed of the atoms. (B) The mass of the atoms.(C) Both the speed and the mass of the atoms. (D) Neither the speed nor the mass.

_____ 10. Choose the best description of heat.(A) Heat is the amount of hotness an object has. (B) Heat is how warm something is.(C) Heat is a measurement of the average kinetic energy of a bunch of particles. (D) Heat is a lack of coolness of an object.(E) Heat is the transfer of energy from one object to another.

_____ 11. Which substance requires the most amount of energy to raise the temperature of 1 g of the substance by 1 C?

(A) Methanol (C = 0.58 cal/gºC) (B) Iron (C = 0.11 cal/gºC)(C) Aluminum (C = 0.21 cal/gºC) (D) Water (C = 1.0 cal/gºC)(E) Vegetable oil (0.40 cal/gºC)

_____ 12. Which requires more energy? Use the space given below if you need to do calculations.(A) Heating 100 g of water from 10ºC to 30ºC (B) Heating 50 g of water from 10ºC to 20ºC(C) Heating 10 g of water from 20ºC to 60ºC (D) Heating 400 g of water from 20ºC to 30ºC(E) They all require the same amount of energy

_____ 13. Which action raises the temperature of a cup of water the most? Space is given below if you need to do a calculation.

(A) Adding 250 cal to 100 g of water at 30C (B) Adding 100 cal to 50 g of water at 30C(C) Adding 700 cal to 400 g of water at 30C (D) Adding 400 cal to 200 g of water at 30C

_____ 14. The specific heat capacity of hydrogen is 3.34 cal/gC. What is the temperature change of 200 g of hydrogen if 500 cal of heat are added?

(A) 0.75C (B) 1.5ºC (C) 8.4ºC (D) 16.7ºC

_____ 15. At what temperature does the substance whose heating curve is shown below boil?

(A) below 10C (B) 10C(C) from 10C to 225C (D) 225C

SHORT ANSWER (5 points each)16. Using complete sentences, explain how particles transfer energy to each other.

17. Imagine you have two blocks of metal, both at different temperatures. A distance of one centimeter separates the blocks. Which substance, when placed between the blocks, will conduct heat better: a gas or a solid? Explain in terms of the particle model. Use complete sentences to explain.

Figure 1: Heating curve of water.

AB

CD

E

Use Figure 1 to answer questions 23-27.

_____ 18. What phase or phases is/are present at stage 4?(A) liquid and gas (B) solid and liquid (C) solid only (D) gas only (E) liquid only



_____ 21. At which point on the heating curve does all of the ice disappear?(A) Point A (B) Point B (C) Point C (D) Point D (E) Point E

_____ 22. Which stage(s) of the heating curve represent a phase change?(A) Stages 1, 3, and 5 (B) Stage 2 only (C) Stage 3 only (D) Stages 2 and 4

_____ 23. The phase change from solid to liquid is called(A) boiling (B) condensation (C) freezing (D) melting (E) sublimation

_____ 24. The phase change from gas to liquid is called(A) boiling (B) condensation (C) freezing (D) melting (E) sublimation

_____ 25. The phase change from liquid to gas is called(A) boiling (B) condensation (C) freezing (D) melting (E) sublimation

26. The freezing point of water is _____________ (include units)

27. The boiling point of water is _____________ (include units)

28. Why does the temperature of a glass of ice water stay at or near the freezing point of water, even on a hot, sunny day? Make sure you describe what is happening to the energy from the sun. (5 pts)

chemistry 2nd semester - rozema's...

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