Chemistry I Final Review

Chemistry I Final Review Name ______

Test Date: ______Time:______Room: ______Proctor______

Mathematics:

1. Convert: a. 15 mg to grams b. 0.00045 km to cm

2. Write in scientific notation or regular form:

a. 156,000,000 b. .00000942 c. 7.5 x 103 d. 8.64 x 10-4

2.5 x 1023 3. Solve = 7.56 x 1013

4. How many significant figures?

a. _____ 23 b. _____ 200,000 c. _____ 0.00055000 d. _____ 1,010

5. What is the density of an object with a mass of 2.94 g and a volume of 38 cm3?

Matter & Energy:

6. What has more kinetic energy-a parked truck or a feather floating in the air? ______

7. Identify as an element (E), compound (C), heterogeneous mixture (M) or solution (S)?

a. ______sodium carbonate b.______sugar water

c. ______carbon d.______rocks and sand

8. What method would you use to separate these substances (electrolysis, paper chromatography, distillation, filtration.)

a. ______sodium chloride b.______isopropyl alcohol & water

c. ______chlorophyll in leaves d.______rocks and water

9. Physical (P) or chemical (C) change?

a.______burning magnesium b. ______melting ice

c.______powdering a sugar cube d. ______iron rusting

10. Convert to Kelvin a. 15°C b. -258°C

11. Convert to °C: a. 59K b. 491K

1 The Atom: isotopic atomic mass electrons protons neutrons symbol number number 12. Complete the following table:

10 8 10

13. How many electrons, protons and neutrons in a:

a. sodium-23 ion b. fluoride-19 ion

Nuclear:

14. Write the nuclear equation for the:

a. alpha decay of uranium-238

b. beta decay of lead-214

c. neutron bombardment of plutonium-239 yields americium-240 and another particle

15. Carbon-14 has a half life of 5700 years. How long will it take for a sample which contains 100. g of carbon -14 to decay to 12.5 g.

The Electron:

16. In terms of electrons, explain why elements give off light (atomic emission spectrum) when an electric current is applied.

17. Write the electron configuration for the following atoms and state how many valence electrons each has: a. potassium atom b. bromine atom

18. Draw the orbital box diagram and the electron dot diagram for Sulfur. How many unpaired electrons does it have? 2 Periodic Table and Periodic Trends:

19. What is a group or family? ______period? ______

20. How many valence electrons do the alkaline earth metals have? ______The halogens? ______

21. What is the ionic charge of the alkali metals? ______How does that affect their reactivity______

22. Which is larger? a. Ca or K b. P or N c. O or O-2

23. Which has the smaller ionization energy? a. Na or Mg b. C or Si

Naming & Bonding:

24. Using the Table of Electronegativities, determine the bond type between:

a. K and Cl b. S and O c. C and H

25. Draw the structural formula for the covalent compound CCl4

26. Draw the lewis-dot diagram for the ionic compound Li2S

27. Name the following ionic compounds

a. NaBr ______b. Ca(NO3)2______

c. FeF3 ______d. Cu2SO3______

28. Write the formulas for the following ionic compounds.

a. potassium oxide ______b. barium chlorite______

c. tin (IV) oxide______d. lead (II) acetate______

29. Write the names or formulas for the following molecular (covalent) compounds.

a. S2O3______b. P2O5______

c. dinitrogen pentoxide______d. sulfur trioxide______

30. Write the formula for the following acids. Complete with acids and Bases Section

a. hydronitric acid______b. hypochlorus acid______

c. HNO2______d. H3P______

Equations:

3 31. Balance the following equations:

a. Na + H2O → NaOH + H2

b. C8H18 + O2 → CO2 + H2O

c. Na + Al2(SO4)3 → Al + Na2SO4

32. Predict the products for the following reactions and balance the equations.

a. Mg + HCl →

b. NaCl 揪e

c. C2H6 + O2 →

d. Al + Cl2 →

e. Ca(OH)2 + AlF3 →

33. Identify the reaction type for each equation above to the left of the letter (S, D, SR, DR, C)

Moles:

34. What is the molar mass of Ca3(PO4)2?

35. Convert: a. 6.5 g of NaCl to moles

b. 3.58 x 1022 atoms of He to liters.

c. 39.7 g C12H22O11 to molecules

36. Determine the percent composition of Al(NO3)3

37. A compound is determined to consist of 85.7 % carbon and 14.3 % hydrogen

a. Determine the empirical formula of the compound.

4 b. If the compound has a molar mass of 56.0 g/mol, determine the molecular formula.

Stoichiometry:

38. How many grams of chlorine gas are needed to react completely with 11.0 g of sodium in the following unbalanced reaction? Na + Cl2 → NaCl

39. How many liters of hydrogen gas are produced when a 0.250 g piece of magnesium is placed in a beaker of hydrochloric acid? Assuming all the Mg is used up. Write the balanced equation first.

40. If 3.50 L of nitrogen gas react with hydrogen gas, how many molecules of ammonia gas are produced at STP? N2 + 3H2 ↔ 2NH3

41. An exothermic /endothermic reaction absorbs heat and its ∆H is negative/positive. (circle one each)

42. If the average kinetic energy of the particles of a gas decreases, what happens to the temperature? ______

- 43. Use the following reaction to answer the questions: 2SO2 + O2 → 2SO3 H= 197.8 kJ

a. Is this an endo or exothermic reaction? ______

b. Write the thermochemical equation for the above reaction (put the heat term in the equation.)

c. What quantity of heat is released when 14.9 g of SO2 reacts according to the following equation?

44. How much heat is released when 432 g of water cools from 71.0 ºC to 18.0 ºC? (Cwater = 4.184 J/g ºC)

5 45. What is the specific heat of aluminum if the temperature of a 28.4 g sample of aluminum is increased by 8.1˚C when 207 J of heat is added?

46. From the following enthalpy changes,

- Cu(s) + Cl2(g) → CuCl2(s) ∆Hº = 206.0 kJ - 2Cu(s) + Cl2(g) → 2CuCl(s) ∆Hº = 136.0 kJ

Calculate the value of ∆Hº for the reaction

CuCl2(s) + Cu(s) → 2CuCl(s)

Gas Laws:

47. If pressure is held constant, what happens to the volume as the temperature is doubled? ______

48. If temperature is held constant, what happens to the volume if the pressure is quadrupled? ______

49. At 75 ºC, a gas has a volume of 3.22 L. What volume will it occupy at 75 K?

50. If the volume of a gas is 19.4 L at 4.99 atm, what is the volume at 1580 mm Hg?

51. If CO2 gas occupies 22.4 L at STP, what will its temperature be if it is compressed to 15.0 L at a new pressure of 2.00 atm?

52. What pressure is required to contain 0.023 moles of nitrogen gas in a 4.2 L container at a temperature of 20.ºC? (Ideal Gas Constant = 0.0821 L•atm / mol•K)

6 Solutions:

53.What is the molarity of a solution formed by mixing 8.0 g of NaOH with enough water to make 150. mL of solution?

54.How many grams of potassium bromide should be added to water to prepare 0.50 L of solution with a molarity of 0.125 M?

55.Using your solubility curve if you dissolve 50. g of NH4Cl at 40 °C what kind of solution do you have? (saturated, unsaturated or supersaturated) circle one

56.Using your solubility curve, what is the solubility of NH3 at 50°C? ______

Reaction Rates:

57. Draw an energy diagram for an exothermic reaction. Label the following items: reactants, products, activation energy of the forward reaction, the activated complex, reaction progress, and potential energy.

58. How does the catalyst speed up a reaction? ______

59. In general the rate of a reaction ______as temperature increases. Equilibrium/LeChatlier:

Answer the following about the classic Haber Process Reaction: N2(g) + 3H2 (g) ↔ 2NH3(g) + Heat

60. If you add nitrogen the forward reaction will increases / decreases. (circle one) 7 61. If you remove ammonia from the reaction vessel, the reaction will shift ______to make more ______.

62. If you heat up the above reaction, the forward reaction will decrease / increase. (circle one)

63. If you increase pressure the forward / reverse reaction will increase. (circle one)

Acids & Bases:

64. An acid turns litmus paper red/blue, has a bitter/sour taste, does/does not react with metals. (circle one each)

65. When an acid and base react the products are usually a ______and ______.

66. What is the pH of a 3.4 x 10−5M solution of HCl? Name this substance. ______

67. Determine the pH of a 0.015 M LiOH solution. Is this an acid, base or neutral substance?

68. a) What is the conjugate acid of NH3? ______

b) Identify the conjugate acid-base pairs in the following reaction.

+ − H2SO4(aq) + H2O(l) → H3O (aq) + HSO4 (aq)

69. In a titration experiment, a 12.5 mL sample of .0175 M NaOH neutralized 14.5 mL of an HNO3 solution. What is the molarity of the HNO3 solution?

Answer Key

Mathematics:

1. a. .015g b. 45 cm 2. a. 1.56 x 108 b. 9.42 x 10-6 c. 7500 d. 0.000864 8 3. 3.3 x 109 4. 2;1;5;3 5. 0.077g/cm3

Matter & Energy:

6. feather 7. C;S;E;M 8. a) electrolysis b) distillation c) paper chromatography d) filtration 9. C;P;P;C 10. 288K; 15K 11. -214 ºC; 218 ºC

12. 23 11 23 11 11 12 11 Na 18 -2 8 O 8 18 10 8 10 65 29 65 29 29 36 29 Cu 19 9 19 9 9 10 9 F

13. a. 11p+, 12nº, 10e- b. 9p+, 10nº, 10e-

238 4 234 214 0 214 1 239 240 0 Nuclear: 14 a. 92U α 2 + Th90 b. 82Pb -1 e + 83 Bi c. 0n + 94 Pu 95 Am + -1 e 15. 17,100 years

Electron:

16. When electrons become excited, they jump to a higher energy level. At this level they are unstable and fall back to a lower energy level. When they fall, they release energy.

17. a. 1s22s22p63s23p64s1 , 1 b. 1s22s22p63s23p64s23d104p5 , 7

        18. , 2 1s 2s 2p 3s 3p

Periodic Table:

19. Group and Family (vertical columns); Period (horizontal row) 20. 2; 7 21. +1; very reactive – loose their 1 valence electron easily 22. a) K b) P c) O-2 23. a) Na b) Si

Bonding & Formulas:

24. a) ionic b) polar covalent c) covalent

25. 26.

27. a) sodium bromide b) calcium nitrate c) iron (III) fluoride d) copper (I) sulfite 28. a) K2O b) Ba(ClO2)2 c) SnO2 d) Pb(CH3COO)2 29. a) disulfur trioxide b) diphosphorus pentoxide c) N2O5 d) SO3 30. a) H3N b) HClO c) nitrous acid d) hydrophosphoric acid

Equations: 9 31.a. 2,2,2,1 b. 2,25,16,18 c. 6,1,2,3 32. & 33. a. Mg + 2HCl → MgCl2 + H2 (Single Replacement) b. 2NaCl → 2Na + Cl2 (Decomposition) c. 2C2H6 + 7O2 → 4CO2 + 6H2O + heat (Combustion) d. 2Al + 3Cl2 → 2AlCl3 (Synthesis) e. 3Ca(OH)2 + 2AlF3 → 3CaF2 + 2Al(OH)3 (Double Replacement)

Mole: Stoichiometry: Heat: 34. 310.3 g/mol 38. 17.0 g Cl2 41. endothermic/positive 22 35. 0.11 mol; 1.33 L; 6.99 x 10 molecules 39. Mg + 2HCl → MgCl2 + H2 42. decreases - 36. 12.7 % Al, 19.7% N, 67.61% O 39. 0.230 L H2 43. a. Exo c. 23.0 kJ 23 37. a. CH2; b. C4H8 40. 1.88 x 10 molecules 43b. 2SO2+ O2→ 2SO3 197.8kJ 44. -95.8 kJ 45. 0.90 J/g°C 46. +70.0 kJ Gases 47. doubles Solutions Equilibrium/LeChatlier 48. quartered 53. 1.3 M 60. increases

49. 0.69 L 54. 7.5 g KBr 61. right, NH3 50. 46.5 L 55. supersaturated 62. decrease

51. 366 K 56. 30 g /100g H2O 63. forward 52. 0.13 atm

Acids & Bases Reaction Rates 64. red, sour, does 65. salt and water Activated Complex 66. hydrochloric acid ; pH = 4.47 67. pH = 12.18 ; base + 68a. NH4 + − b. H2SO4(aq) + H2O(l) → H3O (aq) + HSO4 (aq) R A B CA CB 69. 0.0151M P

Reaction Progress

58. Catalyst speeds up the reaction by lowering the energy of activation. 59. increases