Unit 5: Bonding. Place a checkmark next to each item that you can do. If a sample problem is given, complete it as evidence.

Transcription

1 Unit 5: Bonding Place a checkmark next to each item that you can do. If a sample problem is given, complete it as evidence. Intramolecular Forces: 1. I can define intramolecular forces and intermolecular forces and give examples of each. Examples: Intermolecular Forces: Examples: 2. I can explain and apply the meaning of BARF as it applies to chemical bonding. 3. I can state the number of valence electrons that an atom attains to be most stable. 4. I can state the three types of chemical bonds. BARF stands for This means that when a bond is FORMED, energy is and when a bond is BROKEN, energy is. Given the balanced equation: N + N N 2 Which statement describes the process represented by this equation? A) A bond is formed as energy is absorbed. B) A bond is formed as energy is released. C) A bond is broken as energy is absorbed. D) A bond is broken as energy is released. Atoms are most stable when they have valence electrons. The three types of chemical bonds are,, and. Ionic Bond: 5. I can define ionic bond, covalent bond, and metallic bond in terms of the types of elements (metals, nonmetals) from which they are formed. Covalent Bond: Metallic Bond:

2 In an ionic bond, the valence electrons of the are to the so that each atom attains a stable octet (like noble gases). In these compounds, the 6. I can define ionic, covalent, and metallic bonds based on what happens to the valence electrons. electronegativity difference is. In a covalent bond, the valence electrons of the two are so that each atom attains a stable octet. In these compounds, the electronegativity difference is. In a metallic bond, positive ions are immersed in. 7. I can determine the compound that has the greatest ionic character. Which of the following compounds has the greatest ionic character? A) LiCl B) CaCl 2 C) BCl 3 D) RbCl Draw Lewis dot diagrams for the following ionic compounds: 8. I can draw a Lewis dot diagram to represent an ionic compound. NaCl CaCl 2 9. I can state the properties of ionic substances. Physical properties of ionic substances are: A solid substance was tested in the lab. The results are shown below. *dissolves in water *is an electrolyte * has a high melting point 10. I can identify a substance as ionic based on its properties. Based on these results, the solid substance could be A) Hg B) AuCl C) CH 4 D) C 12 H 22 O 11 Based on bond type, which compound has the highest melting point? A) CH 4 B) C 12 H 22 O 11 C)NaCl D) C 5 H I can state the number of electrons that are shared in single and multiple covalent bonds. In a single covalent bond, electrons or pair is shared. In a double covalent bond, electrons or pairs are shared. In a triple covalent bond, electrons or pairs are shared.

3 Draw Lewis dot diagrams for the following molecular substances and identify their shapes. H 2 O CO I can draw a Lewis dot diagram to represent a molecular (covalently bonded) substance and identify its shape as linear, bent, trigonal pyramidal, or tetrahedral. I 2 CH 4 NH 3 CHCl I can state the properties of molecular substances. Physical properties of molecular substances are: 14. I can identify a substance as molecular based on its properties.

4 15. I can state the type of bonding that occurs in compounds containing polyatomic ions. 16. Given the chemical formula for a compound, I can determine the type(s) of bonding in the compound. Compounds containing polyatomic ions have bonding. State the type(s) of bonding in the following compounds: NaCl CO Hg Na 3 PO 4 Explain, in terms of valence electrons, why the bonding in methane (CH 4 ) is similar to the bonding in water (H 2 O). 17. In terms of valence electrons, I can find similarities and differences between the bonding in several substances. Explain, in terms of valence electrons, why the bonding in HCl is different than the bonding in NaCl. Polar covalent bonds are formed when nonmetals share electrons. The 18. I can explain the difference between a polar covalent bond and a nonpolar covalent bond. electronegativity difference is. Nonpolar covalent bonds are formed when nonmetals share electrons. The electronegativity difference is. 19. I can explain how to determine the degree of polarity of a covalent bond. 20. I can explain why one covalent bond is more or less polar than another covalent bond. The degree of polarity of a covalent bond is determined by the between the elements. Explain, in terms of electronegativity difference, why the bond between carbon and oxygen in a carbon dioxide molecule is less polar than the bond between hydrogen and oxygen in a water molecule. 21. I can determine which end of a polar covalent bond is slightly negative and which end is slightly positive and explain why. Draw a water molecule and include slight charges. Explain why you assigned each atom its charge.

5 22. I can define symmetrical and asymmetrical. Symmetrical: Asymmetrical: SNAP means. 23. I can explain and apply the meaning of SNAP as it relates to determining molecule polarity. Why is a molecule of CH 4 nonpolar even though the bonds between the carbon and hydrogen are polar? A) The shape of the CH 4 molecule is symmetrical. B) The shape of the CH 4 molecule is asymmetrical. C) The CH 4 molecule has an excess of electrons. D) The CH 4 molecule has a deficiency of electrons. Explain, in terms of charge distribution, why a molecule of water is polar. Determine which molecules are polar and which are nonpolar. Justify your answer. H 2 O CO I can determine if a molecular is polar or nonpolar. I 2 CH 4 NH 3 CHCl 3 Dipole-Dipole: Dispersion: 25. I can define the different types of intermolecular forces. Hydrogen Bonding: Molecule-Ion Attraction:

6 26. I can state the relationship between polarity and intermolecular force strength. 27. I can state the relationship between size of the molecule and intermolecular force strength. 28. I can state the relationship between the strength of the intermolecular forces and vapor pressure. 29. Given the physical state of some substances, I can compare the relative strength of the intermolecular forces. As the polarity of the molecule, the strength of the forces. As the size of the molecule, the strength of the forces. As the strength of the forces, vapor pressure. At STP, iodine (I 2 ) is a crystal and fluorine (F 2 ) is a gas. Compare the strength of the intermolecular forces in a sample of I 2 at STP to the strength of the intermolecular forces in a sample of F 2 at STP. 30. Given the boiling points (or freezing points) of some substances, I can compare the relative strength of the intermolecular forces. At STP, CF 4 boils at C and NH 3 boils at C. Which substance has stronger intermolecular forces? Justify your answer. Which compound has hydrogen bonding between its molecules? 31. I can answer questions about hydrogen bonding. A) CH 4 B) CaH 2 C) KNO 3 D) H 2 O The relatively high boiling point of water is due to water having A) hydrogen bonding B) metallic bonding C) nonpolar covalent bonding D) strong ionic bonding In which system do molecule-ion attractions exist? A) NaCl (aq) B) NaCl (s) C) C 6 H 12 O 6 (aq) D) C 6 H 12 O 6 (s) Which diagram best illustrates the ion-molecule attractions that occur when the ions of NaCl (s) are added to water? 32. I can answer questions about molecule-ion attraction.