1. Density is an (A) intensive, (B) extensive property.

2. A basket ball has volume of 7,400 mL. How many gallon is it ?
A(1.0), B(1.5), C(2.0), D(2.5), E(3.0).

3. Three measurements are made to determine density (g/mL) of a metal.
If the true value is 4.50 g/mL, whose are precise but not accurate?
(Andy) 4.49,4.50,4.51; (Beth) 3.50,4.50,5.50; (Chuck) 3.49,3.50,3.51; (Dave) 4.50,5.50,6.50.

4. The SI Unit of pressure is
(A) kg/(m^2.s²), (B) kg/(m^.s²), (C) kg^.m²/s², (D) kg^.m/s².

5. At what temperature, values in the Celsius and Fahrenheit scales become same ?
A(-40), B(-32), C(-20), D(20), E(32), F(40).

6. A unit cell of a crystal of gold metal has a volume of 67.6 cubic Angstroms.
What is this volume in cubic decimeters?
(A) 6.76x10^-26, (B) 6.76x10^-18, (C) 6.76x10^-8, (D) 6.76x10^-6 cm³.

7. Numbers of protons, neutrons, & electrons in a ²³₁₁Na⁺ ion are,
A(11;12;11), B(10;12;11), C(11;23;11), D(11;12;10), E(11;12;12), respectively.

8. Which is the largest number?
(A) number of stars in the observable universe(10²²), (B) the Avogadro Number(=1mol),
(C) number of sand grains in a beach with 10 mile length, 100 yard width and 1 yard depth,
(assume that density of sand = 2.7g/mL, & an average mass of a sand grain =1mg),
(D) number of water molecules in a drop of water (1drop=0.05mL).
(E) number of air molecules in this room (20ft x 20ft x 9ft).

9. Which one is the largest amount of energy ?
(A) Ionization Energy of 1 mol of sodium atoms (=496 kJ/mol).
(B) energy required to break 1 mol of C-C single bond(=82.7kcal/mol),
(C) energy of 2 mol of a red light with a wavelength of 600nm,
(D) energy of 1 mol of violet light with a wavelength of 400nm.
(E) energy equivalent of a billionth of a gram of mass (E=mC²).

10. Which is a transition elements?
(A) Na, (B)Mg, (C)Al, (D) Fe, (E) Se.

11. Which formula is for sodium bicarbonate?
(A) NaC₂, (B) NaCO₃, (C) Na₂CO₃, (D) NaHCO₃, (E) Na(CO₃)₂.

12. The formulas for nitride, nitrite, and nitrate are,
(A) NO^-, NO₂^-, NO₃^-, (B) NO₂^-, NO^-, NO₃^-, (C) NO₂^-, NO^2-, NO₃^-, (D) N^3-,NO₂^-,NO₃^-, respectively.

13. Ions that are found in some polluted water are:
A(Mg²⁺, SO₄^2-, Cl^-); B(Hg²⁺, Pb²⁺, PO₄^3-); C(Ca²⁺, Cl^-,HCO₃^-), D(Na+, Cl^-, HCO₃^-).

14. What is charge on Al in Al₂O₃?
(A) 1, (B) 2, (C) 3, (D) -2, (E) -3.

15. Which one is soluble in water?
(A) KNO₃, (B) AgCl, (C) BaCO₃, (D)PbI, (E) PbSO₄.

16. Estimate molar concentration of acetic acid, CH₃COOH, in a vinegar (5%, d=1.04g/mL).
A(0.1), B(0.2), C(0.5), D(1.0), E(2.0) M.

17. Balance the decomposition of baking soda(NaHCO₃, Sodium bicarbonate) upon heating to salt, water and carbon dioxide.
      (   ) NaHCO₃  →  (  ) Na₂CO₃  +  (  ) H₂O  +  (  ) CO₂
(1) What is the sum of all coefficient in the balanced equation?
(2) What volume (in liters) of CO₂ gas at 75 ^oC and 756 mmHg will be produced from 26.8g (=0.945 oz).
     A(5; 4.6), B(5; 4.8), C(5; 5.0), D(6; 4.6), E(6; 4.9).

18. Acrylic acid, used in the manufacture of acrylic plastics,
has a composition of 50.0% C, 5.6% H, and 44.4% O.
What is its empirical formula? (                 )

19. A steel cylinder has a bursting point of 10,000 psi.
It is filled with a nirtogen gas at a pressure of 2,500 psi at 20 ^oC.
What are these pressure in atm? If the tank is exposed to 500 ^oC, will it explode?
A(860; 210; Yes), B(860; 210; No), C(680; 170; Yes), D(680; 170; No).

20. A mass of gas vapor with a volume of 200 mL at 90 ^oC and 745 mmHg is measured
to be 0.540 g. Find the molar mass of this compound for identification.
A(H₂), B(N₂), C(Ne), D(Kr), E(Cl₂) g,

21. Calculate an rms velocity of O₂ molecules in this room (at 20^oC),
and compare it with a speed limit on a highway (55MPH) [1mi=1.609km].
They move about (A) 2, (B) 20, (C) 200, (D) 2,000 times faster than the cars.

22. The ideal gas molecule has only a(n)
(A) Volume, (B) Mass, (C) Intermolecular Force, (D) Color.

23. Which real gas is the closest to the ideal gas ?
(A) He, (B) Ne, (C) N₂, (D) O₂, (E) CO₂, (F) H₂O(vapor).

24. Which radiation has the highest energy?
(A) Gamma rays, (B) X-rays, (C) Blue light, (D) Yellow light, (E) Radio waves.

25. What observations supports "Electromagnetic radiation has wave properties"?
(A) Emission spectrum of hydrogen, (B) The photoelectric effect, (C) Scattering of a particles, (D) Cathode "rays", (E) Diffraction.

26. What is maximum number of electrons allowed in the M shell?
(A) 2, (B) 8, (C) 18, (D) 32, (E) 50.

 27. Which atom is the largest?
(A) H, (B) Al, (C) Si, (D) P, (E) N.

28. Al is the (A) most, (B) 2nd, (C) 3rd, (D) 4th, (E) 5th abundant element in Earth crust.

29. Which nuclei is NOT formed during a NORMAL life of a star?
(A) Na, (B) Al, (C) Ca, (D) Cr, (E) Au.

30. Fe³⁺ has an electronic configuration of
A([Ar]3d⁶4s²), B([Ar]3d⁸), C([Ar]3d³4s²), D([Ar]3d⁵), E([Ar]4s²).

31. Which one does not have a noble gas configuration ?
(A) P^3-, (B) Al³⁺, (C) F^-, (D) K⁺, (E) Zn²⁺

32. What is the deBroglie wavelength of an electron moving with a velocity which is 1.0x10^-3 times the speed of light?
A(0.5), B(1.65), C(2.5), D(4.5), E(5.5) nm.

33. Which atom is the most difficult to ionize, having the largest ionization energy?
(A) Mg, (B) Ca, (C) Sr, (D) Ba, (E) Ra.

34. An element X of Group IIA reacts with Y of Group VA. Which is true concerning the elements or compound?
(A) X is a nonmetal,
(B) Y is a metal,
(C) The compound's formula is X₃Y₂,
(D) The compound would be covalent.

35. Which one is a basic oxide ?
(A) MgO, (B) CO₂, (C) NO₂, (D) SO₂, (E) Cl₂O₇.

36. Values of electronegativity for H, C and O are
A(2.1, 3.5, 2.5), B(2.5, 2.1,3.5), C(3.5, 2.5, 2.1), D(2.1, 2.5, 3.5), respectively.

37. (a) B-H, (b) C-H, (c) N-H, (d) O-H bond is the most polar bond among the four.
This is because the electronegativity difference between the two atoms is the (e) largest, (f) smallest.
A(a,e), B(b,e), C(c,e), D(d,e), E(a,f), F(none of these).

37b. Which one is the most polar compound?
(A) H₂S, (B) Cl₂, (C) HCl, (D) HBr, (E) HI.

37c. Which one is the least polar compound?
(A) Chlorophyll a, C₅₅H₇₂MgN₄O₅, (B) Chlorophyll b, C₅₅H₇₀MgN₄O₆,
(C) Xanthophyll, C₄₀H₅₆O₂, (D) Carotene, C₄₀H₅₆.

38. Which set contains all ionic compounds?
(A) LiCl and CCl₄, (B) KI and SCl₄, (C)SbF₃ and CCl₄, (D) KF & SCl₄, (E) LiCl and Mg₃N₂, (F) NaCl and SbF₃.

39. (a) NaCl, (b) NaBr, (c) NaI, (d) LiCl, (e) LiI has the least lattice energy to be most soluble in water.
This is the interionic distance in this compound is the (f) largest, (g) smallest among the five
to have the least Coulomb's Force. A(a,f), B(b,f), C(c,f), D(d,f), E(e,f), F(none of these).

40. Which molecule is not polar at all, having zero diploe moment?
(A) H₂O, (B) H₂S, (C) SO₂, (D) NO₂, (E) CO₂.

41. There are four kinds of bond in the formic acid (HCOOH) molecule. Which bond length is the longest (140pm )?
(A) C-H, (B) C-O, (C) C=O, (D) O-H.

42. The bond energy of a C-C single is 346 kJ/mol. Bond energy of C=C double bond would be
(A) 167, (B) 346, (C) 602, (D) 835 kJ/mol.

43. Which of these molecules has a trigonal pyramidal geometry?
(A) O-S=O,  (B) Cl-O-Cl,  (C) H-C=O,  (D) BF₃,  (E)NH₃.

44. In the molecule ethylene, C₂H₄, the orbitals used by carbon are
(A) not hybridized, (B) sp hybridized, (C) sp2 hybridized, (D) sp3 hybridized, (E) dsp hybridized.

45A. All of the following may change during a chemical reaction except
A(total volume), B(temperature), C(Density), D(total # of molecules), E(total # of atoms) of the system.

45B. In general, a change in a system will occurs if the system's heat content (enthalpy) can be (a) increased, (b) decreased, and/or if the system can be (c) more, (d) less, disordered.
A(a,c), B(a,d), C(b,c), D(b,d). 

Key

ANSWER any 2 out of following 6. You must show all of your work. Circle the Question Numbers you selected. 10 pts each.

I. Carol accumulated 10,000 miles in 1993 on her car with 25 MPG(mi/gal). The average gasoline cost was $1.125/gal. The car weighs 1,200 kg (=2,650 lbs). Density of the gasoline is 0.7025g/mL at 20^oC.

(1) How many gal, kg, lb, and mol of gasoline she consumed last year? Which is heavier the car or the gasoline it consumed/year?

(2) How much was the annual expenditure on the gasoline (in $)?

(3) Balance the combustion of gasoline: (    )C₈H₁₈+(    )O₂  →  (    )CO₂+(    )H₂O

(4) How many mol, kg, and lb of O₂ gas her car consumed last year?

(5) How many mol, L of CO₂ gas the car generated last year?

(6) How many mol, kg of H₂O vapor the car generated last year? Which is heavier, the car or the amount of water it generated/year?

(7) Find the mass (both in kg & lb) of the water vapor generated when you drive from Atlanta to Washington, DC(610mi). Which is heavier the water or your own weight?

II. Expalin the photoelectric effect and its important application. III. An e- in an H atom relaxed to its ground state energy level(n=1) from an excited level (n=3) with an emission of a photon (i.e., electro-magnetic wave, EMW).

(1) Calculate an energy of the EMW (energy/photon), (2) frequency and (3) wavelength,

(4) This is an (X-ray, Ultra- Violet, Violet, Blue, Yellow, Red, Infra-Red) (Circle).

(5) Calculate the energy per mole of photons (in kJ/mol) (=energy/photon x N_A).

(6) The ionization energy of cesium (Cs) is 376 kJ/mol. Cs is one of the most ionizable metal that is used in the photo-tube of a spectrophotometer for its excellent photoelectric effect. The energy of the photons is large enough to knock electrons off from Cs metals (i.e., Cs → Cs⁺ + e^-) (True, False) (Circle).

IV. Explain in details the formation of covalent, polar and ionic bonds in terms osf a difference in electronegativity values of two participating atoms.

V. Three molecules BF₃, NH₃, and ClF₃ has a same general molecular formula of AX₃, yet their 3-D structures differs from one another significantly. Make three big columns for easier comparisons to answer the following:

(1) Write down Lewis Electron-Dot formula BF₃(1st column), NH₃(2nd), and ClF₃(3rd).

(2) Determine the steric numbers of the central atoms for for each.

(3) Determine the electronic geometry.

(4) Determine the molecular geometry.

(5) Specify hybrid orbital types for each.

(6) Which is symmetrical with respect to a point(a center of the molecule)?

(7) Which is non-polar?

(8) Which has the weakest intermolecular force?

(9) Which would be most soluble in a non-polar solvent?

VI. We human breathe 12 times a minute. During each breath, 500 mL of air is taken to the lung then exhaled. Assuming the mole % of CO₂ in inhaled and exhaled air are 0.04 % and 4.5 % respectively, answer the following questions to two significant figures.

(1) What volume of carbon dioxide is given off by lung in each breath ?

(2) How many moles of carbon dioxide is given off by lung in each breath ?

(3) What is the daily carbon dioxide production in lbs ?

(4) Assuming average mass of a human is 60kg, which is heavier an annual production of CO₂ per person or a mass of a person ? 

 

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T5SS1211