Spring 2020 Study Union Review CHM 2045 / Chemistry 1

April 18th from 12:00 – 2:00 PM Mixture of multiple and free-response.

Disclaimer: This review is not meant to be an exhaustive review of what will be on the ACS exam. This is guide I (Sunmi Jin) have compiled myself using the course textbook, “A Molecular Approach” 4th edition by

Nivaldo Tro and CHM 2045 course material.

1. Classify each substance as a pure substance or mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogenous or heterogenous (multi-part question)

a. Sweat: ____________________ b. Carbon dioxide: ____________________ c. Aluminum: ____________________ d. Vegetable soup: ____________________

2. A small airplane takes on 245 L of fuel. If the density of the fuel is 0.821 g/mL, what

mass of fuel has the airplane taken on? a. 201 * 103 g b. 201 g c. 201 kg d. 245,000 mL e. 201 * 103 mL

3. An acetaminophen suspension for infants contains 80mg/0.80mL suspension. The

recommended dose is 15mg/kg body weight. How many mL of this suspension should be given to an infant weighting 14lb? (1 kg = 2.20462 lb) Assume two significant figures.

a. 9.5 mL b. 95.2 mL c. 0.95 mL d. 2.1 mL e. 21 mL

4. A hydrogen filled balloon is ignited and 1.50 g of hydrogen is reacted with 12.0 g of

oxygen. What is the mass of water vapor that forms? (Assume that water vapor is the only product.)

a. 13.5 mol b. 13.5 g c. 1.35 mol d. 1.35 g e. .75 mol

5. Fill in the blanks to complete the table (fill in the blank)

Symbol Ion Formed Number of electrons in ion

Number of protons in ion

Ca Ca2+ - - - Be2+ 2 -

Se - - 34 In - - 49

6. Calculate the number of atoms in a sample 1.87 g Bi.

a. 8.95*10-3 b. 5.39*1018 c. 8.95*10-6 d. 6.02*1023 e. 5.39*1021

7. Write the balanced chemical equation for the reaction for aqueous sodium carbonate with

aqueous copper (II) chloride to form solid copper (II) carbonate and aqueous sodium chloride.

a. Na2CO3 (aq) + CuCl2 (aq) à CuCO3 (s) + 3 NaCl (aq) b. 2 Na2CO3 (aq) + CuCl2 (aq) à CuCO3 (s) + 2 NaCl (aq) c. Na2CO3 (aq) + CuCl2 (aq) à CuCO3 (s) + NaCl (aq) d. Na2CO3 (aq) + CuCl2 (aq) à CuCO3 (s) + 2 NaCl (aq) e. 2 Na2CO3 (aq) + 3 CuCl2 (aq) à 3 CuCO3 (s) + 2 NaCl (aq)

8. Calculate the empirical formula for caffeine based on its elemental mass percent

composition. C: 49.48% , H: 5.19% , N: 28.85% , O: 16.48% a. C4H5N2O b. C10HN6O3 c. CH2NO2 d. C2H6N8O2 e. C7HN3O2

9. Give the acids their proper, respective names: H3PO4 and H2SO3.

a. Acidic phosphate and sulfuric acid. b. Phosphoric acid and sulfurous acid. c. Phosphatidyl acetate and sulfuric acid. d. Phosphorous acid and sulfurous acid. e. Phosphoric acid and sulfuric acid.

10. Copper (II) fluoride contains 37.42% F by mass. Calculate the mass of fluorine in grams

that is in 55.5 g of copper (II) fluoride. a. 62.4 g b. 34.7 g c. 41.6 g d. 79.2 g e. 20.8 g

11. Urea (CH4N2O) is a common fertilizer that is synthesized b the reaction of ammonia

(NH3) with carbon dioxide:

2 NH3 (aq) + CO2 (aq) à CH4N2O (aq) + H2O (l) In an industrial synthesis of urea, a chemist combines 136.4 kg of ammonia with 211.4 kg of carbon dioxide and obtains 168.4 kg of urea. Determine the limiting reagent, the theoretical yield of urea, and the percent yield for the reaction.

a. Limiting reagent: NH3 , theoretical yield: 480.8 kg , percent yield: 35.02% b. Limiting reagent: CO2 , theoretical yield: 70.04 kg , percent yield: 24.04% c. Limiting reagent: NH3 , theoretical yield: 240.4 kg , percent yield: 70.04% d. Limiting reagent: CO2 , theoretical yield: 288.5 kg , percent yield: 58.37% e. Limiting reagent: NH3 , theoretical yield: 70.04 kg , percent yield: 24.04%

12. Determine whether each compound is soluble or insoluble.

a. AgNO3: ________________ b. PbSO4: ________________ c. KNO3: ________________ d. (NH4)2S: ________________

13. Write the products and the balanced net ionic equations for the following reaction.

Na3PO4 (aq) + NiCl2 (aq) à ____________________________ _______________________________________________________

14. Write the products and a balanced complete ion equation for the following reaction. HC2H3O2 (aq) + K2CO3 (aq)à ____________________________

__________________________________________________________

15. Determine whether the reaction is a redox reaction and identify the oxidizing agent (OA) and the reducing agent (RA).

Pb(NO3)2(aq) + Na2SO4(aq) à PbSO4(s) + 2 NaNO3(aq)

a. Yes; OA= lead; RA= nitrate b. No; N/A c. Yes; OA= sodium; RA= sulfate d. No; OA= oxygen; RA= nitrate e. Yes; OA= oxygen; RA= sulfate

16. If 123 mL of a 1.1 M glucose solution is diluted to 5.0 L, what is the molarity of the

diluted solution? a. 0.044 M b. 27.06 M c. 44.71 M d. 0.027 M e. .5590 M

17. The air within a piston equipped with a cylinder absorbs 565 J of heat and expands from

an initial volume of 0.10 L to a final volume of 0.85 L against an external pressure of 1.0 atm. What is the change in internal energy of the air within the piston?

a. 489.0 J b. 564.25 J c. 565.0 J d. 490.0 J e. 641.0 J

18. The propane fuel (C3H8) used in gas barbeques burns according to the thermochemical

equation C3H8(g) + 5 O2(g) à 3 CO2(g) + 4 H2O(g)

∆H°rxn = - 2044kJ If a pork roast must absorb 1.6 • 103 kJ to fully cook, and if only 10% of the heat produced by the barbeque is actually absorbed by the roast, what mass of CO2 is emitted into the atmosphere during the grilling of the pork roast?

a. 10.33 kg b. 1033 g c. 7.827 kg d. 78.27 g e. 10.33 g

19. A silver block, initially at 58.5 °C, is submerged into 100.0 g of water at 24.8 °C, in an

insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 26.2 °C. What is the mass of the silver block? (specific heat of silver = 0.235 J/g•Cº, water = 4.18 J/g•Cº)

a. 39.48 g b. 41.03 g c. 77.09 g d. 29.23 g e. 34.22 g

20. Calculate ∆Hrxn for the reaction:

5 C(s) + 6 H2(g) à C5H12(l)

Use the following reactions and given ∆H’s: C5H12(l) + 8 O2(g) à 5 CO2(g) + 6 H2O(g) ∆H = – 3244.8 kJ C(s) + O2(g) à CO2(g) ∆H = – 393.5 kJ 2H2(g) + O2(g) à 2H2O(g) ∆H = – 483.5 kJ

a. - 173.2 kJ b. 173.2 kJ c. - 4088.8 kJ d. 367.8 kJ e. - 49.01 kJ

21. A nitrogen laser pulse with a wavelength of 337 nm contains 3.83 mJ of energy. How

many photons does it contain? a. 5.89 • 10-19 J b. 4.23 •1016 J c. 5.89 • 10-19 photons d. 1.54 • 1016 photons e. 6.49 • 1015 photons

22. Calculate the wavelength of an electron traveling with speed of 2.65 • 106 m/s. The mass

of an electron is 9.11 • 10-31 kg a. 3.13 • 10-10 m b. 9.32 • 10-10 m c. 3.44 • 10-10 m

d. 2.74 • 10-10 m e. 6.92 • 10-10 m

23. Which set of three quantum numbers does not specify an orbital in the hydrogen atom? a. n = 2 ; l = 1 ; m1 = -1 b. n = 3 ; l = 3 ; m1 = -2 c. n = 2 ; l = 0 ; m1 = 0 d. n = 3 ; l = 2 ; m1 = 2 e. n = 2 ; l = 1 ; m1 = 0

24. Determine the wavelength of light emitted when an electron in a hydrogen atom makes a

transition from an orbital in n = 6 to an orbital in n = 5 a. 746 nm b. 2.6644 • 10-20 nm c. 7460 nm d. 2664 nm e. 7.46 • 10-6 nm

25. The full electron configuration for Ne is:

a. 1s22s22p6 b. 1s22s22p4 c. 1s22s22p63s23p6 d. 1s22s22p5 e. 1s22s22p63s23p4

26. Which outer electron configuration would you expect to belong to a reactive metal?

a. ns2 b. ns2np6 c. n2np5 d. ns2np2

27. According to Coulomb’s law, if the separation between two particles of the same charge

is doubled, what happens to the potential energy of the two particles? a. It is twice as high as it was before the distance separation. b. It is one-half as high as it was before the separation. c. It does not change. d. It is one-fourth as high as it was before the separation.

28. Arrange this isoelectronic series in order of decreasing radius: F-, O2-, Mg2+, Na+

____________________________

29. Write the electron configuration for each ion:

a. O2- : ____________________________

b. Br-: ____________________________

c. Sr2+: ____________________________

d. Co3+: ____________________________

30. Consider this set of ionization energies. (78)

IE1 = 578 kJ/mol IE2 = 1820 kJ/mol IE3 = 2750 kJ/mol IE4 = 11,600 kJ/mol

To which third-period element do these ionization values belong? ________________

a. Phosphorous b. Chlorine c. Scandium d. Aluminum e. None of the above

31.

32. Explain the trend in lattice energies (LE) of the alkaline earth metal oxides in terms of absolute value.

a. Radius increases with the elements, so distance between cation and anion decreases. LE increases because potential energy decreases with distance.

b. Radius decreases with the elements, so distance between cation and anion increases. LE decreases because potential energy decreases with distance.

c. Radius increases with the elements, so distance between cation and anion increases. LE decreases because potential energy decreases with distance.

d. Radius decreases with the elements, so distance between cation and anion decreases. LE increases because potential energy decreases with distance.

33. Use formal charge to identify the better Lewis structure.

34. Draw the best Lewis structure for PO43- using formal charges. Include resonance structures.

A. B.

35. Hydrogen, a potential future fuel, can be produced from carbon (from coal) and steam by this reaction:

C(s) + 2 H2O(g) à 2 H2(g) + CO2(g)

Use the average bond energies below to calculate ∆Hrxn for the reaction.

a. – 6.14 J b. 238.4 kJ c. 614 kJ d. – 39.42 kJ e. – 614 kJ

36. Which species has the smaller bond angle, ClO4- or ClO3-? Why?

a. ClO4- because it has more oxygens. b. ClO3- because it has a lone pair that causes groups to crowd closer together. c. ClO4- because it has more electron groups. d. ClO3- because it has two lone pairs that causes groups to crows closer together. e. ClO4- because it is tetrahedral while ClO3- is trigonal planar.

37. The ball-and-stick model shows the molecular geometry of a generic molecule. Provide the correct molecular geometry and explain what is wrong with it, given the number of bonding groups and lone pairs.

a. Octahedral; there should not be any lone pairs present. b. Tetrahedral; the bonding pairs should be around the equator while the lone pairs

should be on the axis. c. Seesaw; the lone pair should have been taken from an equatorial position. d. Square pyramidal; the second lone pair should have been taken from the opposite

side of the central atom. e. Pyramidal; the lone pair should have been taken from the axial position.

38. Does CCl4 contain polar bonds? Is the molecule itself polar?

a. Yes; yes. b. No; no. c. Yes; no. d. No; yes. e. Not enough information available.

39. Indicate hybridization around each interior atom.

a. 1.sp3 | 2.sp3 | 3.sp2 | 4.sp2 | 5.sp b. 1.sp3 | 2.sp3 | 3.sp3 | 4.sp2 | 5.sp3 c. 1.sp2 | 2.sp3 | 3.sp3 | 4.sp2 | 5.sp d. 1.sp3 | 2.sp3 | 3.sp2 | 4.sp2 | 5.sp3 e. 1.sp2 | 2.sp3 | 3.sp2 | 4.sp2 | 5.sp

1 2

3

4 5

40. Determine the hybridization around carbon in H2CO. a. sp b. sp2 c. sp3 d. sp3d e. sp3d2

41. What is the density of a sample of argon gas at 55º C and 765 mmHg?

a. 2.99 g/L b. 1.13 • 103 g/L c. 1.49 g/L d. 8.91 g/L e. 10.0 g/L

42. A 255-mLgas sample contains argon and nitrogen at a temperature of 65 °C. The total

pressure of the sample is 725 mmHg, and the partial pressure of argon is 231 mmHg. What mass of nitrogen is present in the sample?

a. 0.324 g nitrogen b. 0.167 g nitrogen c. 0.0837 g nitrogen d. 0.870 g nitrogen

43. Which gas sample has the greatest volume at STP?

a. 10.0 g Ar b. 10.0 g Kr c. 10.0 g Xe d. None of the above (They all have the same volume.

44. A gas sample has a volume of 178 mL at 0.00 °C. The temperature is raised (at constant

pressure) until the volume is 211 mL. What is the temperature of the gas sample in °C at this volume?

a. 0.00°C b. 324°C c. 0.00 K d. 51°C e. 51 K

45. A 1.25 g gas sample occupies 663 mL at 25° C and 1.00 atm. What is the molar mass of

the gas? a. 0.258 g/mol b. 0.0461 g/mol c. 3.87 g/mol d. 1.24 g/mol e. 46.1 g/mol