Multiple Choice. Multiple Choice

Size: px

Start display at page:

Download "Multiple Choice. Multiple Choice"

Dorcas Pierce
5 years ago
Views:

1 1. At what temperature in degree Celcius is the value in degree Fahrenheit twice of that in degree Celcius? A) 160 o C B) o C C) 6.4 o C D) 22.2 o C E) 32 o C 2. The correct name for NaOCl is, A) Sodium hypochlorite B) Sodium oxygenchloride C) Sodium chlorite D) Sodium chlorate E) Sodium chloro oxygenate 3. The chemical behavior of an atom is directly determined by A) the number of electrons it has. B) the mass of the atom. C) the number of neutrons it has. D) the number of protons it has. E) the identity of an isotope of a particular element.

2 4. Which ion has the INCORRECT charge? A) Xe - B) Te 2- C) Ba 2+ D) I - E) S 2-5. Which of the following samples contains the greatest number of atoms? A) 2.0 mole of Ar B) 100 g of Pb C) 0.1 mole of Fe D) 5 g of He E) 20 million O 2 molecules 6. How many grams of Cl 2 can be prepared from the reaction of 16.0 g of MnO 2 and 30.0 g of HCl according to the following chemical equation? MnO 2 + 4HCl MnCl 2 + Cl 2 + 2H 2 O A) 13.0 g B) 0.82 g C) 5.8 g D) 14.6 g E) 58.4 g

3 7. A g sample of mannitol, a sugar found in seaweed, is burned completely in oxygen to give g of carbon dioxide and g of water. The empirical formula of mannitol is, A) C 3 H 7 O 3 B) CHO C) CH 7 O 3 D) C 3 H 2 O E) CH 2 O 8. A mg sample of potassium dichromate (K 2 Cr 2 O 7 ) is dissolved in enough water to make 200 ml of solution. The molarity of the K + ions in this solution is, A) 2.71 x 10 3 M B) 1.00 x 10 3 M C) x 10 3 M D) 2.50 x 10 2 M E) 4.00 x 10 5 M 9. The effusion rate of an unknown gas is ml/min and the effusion rate of oxygen gas under identical experimental conditions is ml/min. The unknown gas would be, A) NO B) NO 2 C) CO 2 D) CO E) CH 4

4 10. What mass of KClO 3 (s) must be decomposed to produce 126 L of O 2 (g) at 133 C and atm? 2KClO 3 (s) 2KCl(s) + 3O 2 (g) A) 272 g B) 24.6 g C) 70.8 g D) 408 g E) 612 g 11. A container is filled with an ideal gas to a pressure of 40.0 atm at 0 C. At what temperature would the pressure be 25.0 atm? A) -102 C B) +102 C C) C D) C E) +135 C 12. How many Rn-O double bonds in the most appropriate Lewis structure of RnO 3? A. 3 B. 2 C. 1 D. 0 E. 4

5 13. The enthalpy of the following reaction CH 2 Br 2 + 2Cl 2 CCl 4 + 2HBr can be approximated using bond energies. Average bond energies are 339 kj/mol for C-Cl, 276 kj/mol for C-Br, 413 kj/mol for C-H, 239 kj/mol for Cl-Cl, and 363 kj/mol for H-Br. Calculate H for this reaction. A. 226 kj B kj C kj D. 452 kj E kj 14. According to the VSEPR model, what is the structure of XeF 2? A. linear B. bent C. trigonal bipyramidal D. tetrahedral E. octahedral 15. How many degrees of temperature rise will occur when a 25.0 g block of aluminum absorbs 10.0 kj of heat? The specific heat of Al is J/g C. A) 444 C B) 0.44 C C) 225 C D) 360 C E) 250 C

6 16. Which one of the following is NOT isoelectronic with Xe? A) Sn 4+ B) Te 2 C) I D) Cs + E) Ba For the molecule below, what is the hybridization for the atoms C 1, N 3 and C 6 in this structure? (Note: Hydrogen atoms are not shown.) C 7 C 6 C 5 N 4 = N 3 C 2 C 1 O 8 A) sp, sp and sp 2 B) sp 3, sp 2 and sp C) sp 2, sp and sp 2 D) sp 3, sp 2 and sp 3 E) sp 2, sp 3 and sp Multiple choice 18. Consider the possibility of a Na 2 molecule. Which of the following electron configurations correctly shows the filling of molecular orbitals after the core electrons? A) (σ 3s ) 2 B) (σ 2s ) 2 C) (σ* 2s ) 2 D) (σ 1s ) 2 E) (σ 2s ) 2 (σ 3s ) 2

7 Multiple choice 19. Bond order is positively correlated to; A) bond energy B) bond length C) bond weakness D) diamagnetism E) paramagnetism Multiple choice 20. The maximum number of electrons that can be placed in a bonding orbital is, A) 2 B) 1 C) 0 D) 3 E) 4 Multiple choice 21. How many sigma (σ) and pi (π) bonds, respectively, are in CH 3 CH 2 CHCHCH 2 CH 3 molecule? A) 17 σ bonds, 1 π bond B) 14 σ bonds, 5 π bonds C) 19 σ bonds, 3 π bonds D) 18 σ bonds, 1 π bond E) 12 σ bonds, 2 π bonds

8 22. Which of the following molecules is paramagnetic? A) NO B) HF C) CO D) CN E) NO Which of the following has the highest bond order? A) C 2 B) C 2 C) C 2 + D) O 2 E) F Which of the following statements is correct? A) The NO 3 ion is planar. B) O 2 is diamagnetic. C) F 2 is paramagnetic. D) The NO 3 ion is tetrahedral. E) N 2 has a bond order of 1.5.

9 25. Which of the following molecules has dipole-dipole intermolecular forces? A) CO B) C graphite C) O 2 D) CH 4 E) SO Which one of the following arrangements is correct in order of increasing boiling point? A) CH 4 < CH 3 Cl < CH 3 OH < RbCl B) CH 4 < CH 3 OH < CH 3 Cl < RbCl C) RbCl < CH 3 OH < CH 3 Cl < CH 4 D) CH 4 < RbCl < CH 3 OH < CH 3 Cl E) CH 3 OH < CH 4 < RbCl < CH 3 Cl 27. The first order diffraction of X-rays by a LiF crystal was detected at an angle of degrees. If the distance between layers of atoms in the LiF crystal is 201 pm, what was the wavelength of the diffracted X-rays? (1 cm = 10 8 Å) A) 2.29 Å B) 4.53 Å C) 1.19 Å D) 3.24 Å E) 5.34 Å

10 28. The vapor pressure of ethanol is 400 mmhg at 63.5 C. Its molar heat of vaporization is 39.3 kj/mol. What is the vapor pressure of ethanol, in mmhg, at 34.9 C? A) B) 1510 C) 200 D) E) A quantitative measure of how efficiently spheres pack into unit cells is called packing efficiency, which is the percentage of the cell space occupied by the spheres. Calculate the packing efficiency of a face-centered cubic crystal. (volume of a sphere is (4/3).π.r 3, where "r" is the radius of the sphere) A) 74 B) 54 C) 84 D) 94 E) A solid that is insoluble in water and nonpolar solvents, melts at temperatures greater that 800 C, and is a poor conductor of electricity could probably be classified as, A) network covalent

11 B) hydrogen-bonded C) ionic D) metallic E) molecular 31. The phase transition with the smallest dependence on pressure is, A) melting B) boiling C) sublimation D) condensation E) vaporization 32. Which of the following liquids would have the highest viscosity at the same temperature? A) HO-CH 2 -CH 2 -OH B) CH 3 Br C) C 2 H 5 OH D) CH 2 Cl 2 E) CH 3 -O-CH 3

12 33. What is the molarity of a 98% H 2 SO 4 by mass solution? The density of the solution is 1.83 g/ml. A) 18.3 M B) 36.6 M C) 5.02 M D) 12.6 M E) 11.5 M 34. The vapor pressure of pure water is mmhg at 25 C. The molality of an aqueous NaCl solution having a vapor pressure of mmhg is, A) 1.89 m B) m C) m D) m E) m 35. What is the percent CdSO 4 by mass in a 1.00 molal aqueous CdSO 4 solution? A) 17.2 % B) % C) % D) 20.8 % E) 24.4 %

13 36. During osmosis, A) pure solvent diffuses through a membrane but solutes do not. B) solutes diffuse through a membrane but solvent does not. C) pure solvent and a solution both diffuse at the same time through a membrane. D) gases diffuse through a membrane into a solution and build up pressure. E) solutes diffuse through a membrane. 37. Calculate the freezing point of a solution made from 22.0 g of octane (C 8 H 18 ) dissolved in g of benzene. Benzene freezes at 5.50 C and its K f value is 5.12 C. kg/mol. A) 1.16 C B) 0.98 C C) 6.66 C D) 12.2 C E) 5.49 C 38. Which of the following will lower the melting point of ice the most? A) Al 2 (SO 4 ) 3 B) (NH 2 ) 2 CO (urea) B) NaCl D) C 6 H 12 O 6 (glucose) E) CH 4 (methane)

14 39. The increasing order of solubility in water of the following substances is, A) O 2 < Br 2 < LiCl < CH 3 OH B) CH 3 OH < LiCl < Br 2 < O 2 C) CH 3 OH < Br 2 < LiCl < O 2 D) LiCl < O 2 < Br 2 < CH 3 OH E) O 2 < LiCl < CH 3 OH< Br Methanol (CH 3 OH) is more volatile than ethanol (C 2 H 5 OH). Which of the following statements is correct in a CH 3 OH / C 2 H 5 OH solution having 0.5 mole fraction of C 2 H 5 OH? A) The boiling point of CH 3 OH is less than the boiling point of C 2 H 5 OH. B) The boiling point of CH 3 OH is greater than the boiling point of C 2 H 5 OH. C) The vapor pressure of CH 3 OH is less than the vapor pressure of C 2 H 5 OH. D) Intermolecular attraction is greater in CH 3 OH than in C 2 H 5 OH. E) CH 3 OH has no vapors and its boiling point becomes greater.

CHM 151 Practice Final Exam

CHM 151 Practice Final Exam CM 151 Practice Final Exam 1. ow many significant figures are there in the result of 5.52 divided by 3.745? (a) 1 (b) 2 (c) 3 (d) 4 (e) 5 2. ow many significant figures are there in the answer when 9.021