6. The molecule which would form a trigonal planar shape would be: a) CH 3 Cl b) SiOF 2 c) NH 3 d) PF 4

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1 A. Multiple Choice. Indicate the correct response on the Scantron card provided. 1. Hydrogen bonding can occur between water molecules and which other substance: a) Carbon tetrachloride b) carbon dioxide c) Ammonia d) sodium fluoride 2. Propane, CH 3 CH 2 CH 3 has a lower melting point than butane, CH 3 CH 2 CH 2 CH 3 because: a) Propane is a more polar molecule than butane. b) Butane has more hydrogens therefore stronger hydrogen bonding. c) Propane has fewer atoms and therefore fewer electrons than butane. d) Butane has weaker London dispersion forces than propane. 3. The VSEPR shape of silicon tetrahydride would be: a) tetrahedral b) trigonal planar c) trigonal pyramidal d) linear 4. Intermolecular forces: a) involve the sharing of electrons between atoms b) are stronger than ionic bonds c) do not exist between nonpolar molecules d) can determine the physical state of a substance at room temperature 5. Polar compounds have higher boiling points than nonpolar compounds because: a) polar molecules are held loosely together and it takes little energy to separate them b) nonpolar molecules have high attractive forces due to the motion of electrons c) attraction between oppositely charged poles holds molecules closer together d) nonpolar molecules are made up entirely of nonpolar bonds. Oct 16 8:18 AM 6. The molecule which would form a trigonal planar shape would be: a) CH 3 Cl b) SiOF 2 c) NH 3 d) PF 4 7. All diatomics exhibit the following intermolecular forces: a) London dispersion forces b) London dispersion forces (negligible) and dipole dipole forces c) London dispersion forces (negligible) and hydrogen bonding c) none of the above 8. Which of the following molecules is polar? a) C 2 I 2 b) COH 2 c) C 2 F 4 d) SiCl 4 9. Which of the following molecules forms a trigonal pyramidal shape? a) HCSBr b) C 2 F 2 c) SF 2 d) PF The correct chemical name for CuCO 3 is: a) copper (II) carbonate b) cuprous carbonate c) copper (I) carbon trioxide d) copper carbonate Oct 16 8:21 AM 1

2 11. The correct chemical formula for nitrous acid is: a) HNO 3 b) HNO 2 c) H 2 N d) H 2 NO The bond between a carbon and a chlorine would be classified as a: a) nonpolar covalent bond b) polar covalent bond c) ionic bond d) double covalent bond 13. For a molecule of carbon tetrafluoride, the following statement is correct: a) All bonds within the molecule are polar, therefore the overall molecule is polar b) The electrons shared between the carbon and fluorine atoms are shared equally. c) All bonds within the molecule are polar, therefore the overall molecule is polar d) The electrons shared between the carbon and fluorine atoms are located closer to the fluorine atoms. 14. Which of the following molecules would exhibit hydrogen bonding? a) CH 3 F b) NH 3 c) OF 2 d) PH 2 F 15. Which of the following substances is most likely to be soluble in water? a) CH 4 b) Si 2 Br 4 c) CH 3 Cl d) CS 2 Oct 16 8:25 AM 16. Carbon tetrachloride does not dissolve in water because: a) Water molecules are more attracted to each other than to CCl 4 molecules b) CCl 4 molecules are highly attracted to each other and therefore will not separate c) Both molecules exhibit hydrogen bonding and therefore cannot form a solution. d) CCl 4 molecules are too large to dissolve in water. 17. One could predict OS 2 to have a higher boiling point than S 2 because: a) OS 2 has more electrons than S 2 b) OS 2 has a higher EN than S 2 c) OS 2 is a polar molecule, whereas S 2 is nonpolar d) S 2 has stronger dipole dipole forces than OS Induced dipoles occur in the following molecules: a) polar molecules only b) polar molecules in which hydrogen is bonded to nitrogen, oxygen or fluorine c) nonpolar molecules only d) all molecules 19. Hydrogen bonding will be strongest in which of the following molecules: a) NH 3 b) H 2 O c) CH 3 OHd) OF In comparing N 2 H 4 and C 2 H 4, which of the following statements is true? a) N 2 H 4 has the higher boiling point as it has hydrogen bonding whereas C 2 H 4 does not. b) Both are nonpolar molecules. N 2 H 4 has the higher boiling point because it has more electrons. c) C 2 H 4 has the higher melting point as it has a higher EN than N 2 H 4. d) C 2 H 4 has the higher melting point as it has higher dipole dipole forces whereas N 2 H 4 has only London dispersion forces. Oct 16 8:27 AM 2

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5 Homework: Unit Project (FINISH!!!) 5