1. Intermolecular and Intramolecular Forces Review

2. In the compound PCl 3, how many valence electrons are present? 1.4 2.8 3.24 4.26

3. How many valence electrons are available in the ion NO 3 - ? 1.16 2.9 3.22 4.24

4. Which type of bond has an electronegativity difference greater than 1.8? 1.ionic 2.metallic 3.nonpolar covalent 4.polar covalent

5. What molecular shape is the compound CCl 4 ? 1.trigonal planar 2.tetrahedral 3.octahedral 4.bent

6. How many bond pairs of electrons exist in a molecule of ammonia (NH 3 )? 1.1 2.2 3.3 4.4

7. What molecular shape is the compound NH 3 ? 1.trigonal planar 2.tetrahedral 3.trigonal pyramidal 4.bent

8. If the electronegativity of H is 2.20 and of Cl is 3.55, which type of bond is formed between H and Cl, when they form hydrogen chloride? 1.Ionic 2.Polar ionic 3.Covalent 4.Polar covalent

9. Which of the following is a polar molecule? 1.CO 2 2.Br 2 3.BCl 3 4. NH 3 5.CH 4

10. Which of the following is a nonpolar molecule? 1.CF 4 2.H 2 O 3.NCl 3 4. NH 3 5.NO 3 -

11. Which is a typical characteristic of an ionic compound? 1.Electron pairs are shared among atoms. 2.The ionic compound has a low solubility in water. 3.The ionic compound is described as a molecule. 4.The ionic compound has a high melting point.

12. Why do atoms share electrons in covalent bonds? 1.to become ions and attract each other 2.to attain a noble-gas electron configuration 3.to become more polar 4.to increase their atomic numbers

13. Which of the following elements can form diatomic molecules held together by triple covalent bonds? 1.carbon 2.oxygen 3.fluorine 4.nitrogen

14. The shape of the methane molecule CH 4 is called ____. 1.tetrahedral 2.square 3.four-cornered 4.planar

15. What causes water molecules to have a bent shape, according to VSEPR theory? 1.repulsive forces between unshared pairs of electrons 2.interaction between the fixed orbitals of the unshared pairs of oxygen 3.ionic attraction and repulsion 4.the unusual location of the free electrons

16. When placed between oppositely charged metal plates, the region of a water molecule attracted to the negative plate is the ____. 1.hydrogen region of the molecule 2.geometric center of the molecule 3.H—O—H plane of the molecule 4.oxygen region of the molecule

17. What is thought to cause the dispersion forces? 1.attraction between ions 2.motion of electrons 3.sharing of electron pairs 4.differences in electronegativity

18. Which of the forces of molecular attraction is the weakest? 1.dipole interaction 2.dispersion 3.hydrogen bond 4.single covalent bond

19. What causes dipole interactions? 1.sharing of electron pairs 2.attraction between polar molecules 3.bonding of a covalently bonded hydrogen to an unshared electron pair 4.attraction between ions