Chemistry Assessment Questions

Ion

1a) What is an ion? Give examples

1b) What is a cation? Give examples

1c) What is an anion? Give examples

2b) How many valence electrons does Ca have and in what orbital do they exist?

2c) What charge would calcium most likely carry when making an ion? Why?

2d) Draw the ground state orbital diagram of the oxygen atom. Label the orbitals.

2e)How many valence electrons does oxygen atom have and in what orbital do they exist?

2f) What charge would oxygen most likely carry when making an ion? Why?

3a) What is electronegativity? Give the electronegativity values for F, O, CI, N, Br, I, C, H

3b)What is the electronegativity trend across the period? Explain your reasoning.

4a)How do you define chemical bonding?

4b)Why do atoms want to form bonds?

4c)What types of chemical bonds exist and how are they defined?

5a) What is an Isoelectronic series? What is unique to members of the series?

5b) Give 3 examples of isoelectronic series

6a) What is a Lewis structure?

6b)Draw the Lewis dot structure for a neutral calcium atom.

6c)Draw the Lewis dot structure for a neutral oxygen atom

6d)Draw the Lewis dot structure for calcium oxide

7a) What is lattice energy? Why is it important?

7b)How much energy is involved by bringing together a calcium ion and an oxygen ion? Draw the 
energy diagram and calculate the lattice energy for CaO.

7b)What is the lattice energy of MgF2? (Problem #62 in Ch. 3 of the book p. 150c) Draw the energy 
diagram.

8a)What is a covalent bond?

8b) What are the types of covalent bonds. Describe each and give an example.

9) Refer to the energy information (text: page 105) on the hydrogen molecule to answer the  following:

9a) Describe what is happening when the nuclei are close to each other.

9b) Describe what is happening when the nuclei are far apart.

9c)Why does an energy well exist in the graph for hydrogen molecule? What does this tell us about  the molecule?

9d)What properties determine if atoms will combine to form covalent bonds?

10a)How many valence electrons do most atoms want to have in order to be stable?

10b)What are the exceptions? Why do they exist? Give examples

11a)How is the relative energy of associated covalent compounds calculated?

Electronegativity

11b)Determine the energy associated with the formation of nitrogen trichloride from its elements,  reaction shown below. Hint: N2 IS N-N, CI2 is CI-CI, and NCI3 IS three N-CI bonds. N2 (g) + 3Cl2 (g)    2NCI3 (I)

12) Determine the energy associated with the combustion of glucose, reaction shown below:   Hint:    H       CO2 IOOks like O=C=O.
H-  C-  O-  H

H / H
H  0   H  H     + 6 O2(g)—+6 CO2(g) + 6 H2O(g)
H   0 — H

13)Compare and contrast non-polar (purely covalent bonds) and polar covalent bonds.

14)Are the bonds in the molecules shown below non-polar, polar or ionic? Name each of the compounds

a) CO2

b) CH4

c) MgO

d) AsCI5

e) PH3
f) SO2

g) SiH4

h) Be3P2

i) ASI5

j) H2S

15) Compare and contrast the properties of ionic compounds with covalent molecules. Make a table of  comparison.

16a)OutIine the steps for drawing a Lewis structure for a molecule or ion.

16b) What is formal charge? How is it calculated? Why is its significance?

17)What atoms do not obey the octet rule? Why?

18) Draw the Lewis structures of the following molecules and calculate the formal charqe for each  atom in the compound as well as the molecule's overall formal charge:

18a) Carbon monoxide Lewis structure.Calculation Formal Charge for each atom.Calculation Formal Charge for molecule

18b) Ammonium ion Lewis structure.Calculation Formal Charge for each atom.Calculation Formal Charge for molecule

18c) Cyanide ion Lewis structure.Calculation Formal Charge for each atom.Calculation Formal Charge for molecule

18d) Phosphate ion Lewis structure

1a) What is an ion? Give examples

1b) What is a cation? Give examples

1c) What is an anion? Give examples

2a) Draw the ground state orbital diagram of calcium atom. Label the orbitals

2b) How many valence electrons does Ca have and in what orbital do they exist?

2c) What charge would calcium most likely carry when making an ion? Why?

2d) Draw the ground state orbital diagram of the oxygen atom. Label the orbitals.

2e)How many valence electrons does oxygen atom have and in what orbital do they exist?

2f) What charge would oxygen most likely carry when making an ion? Why?

3a) What is electronegativity? Give the electronegativity values for F, O, CI, N, Br, I, C, H

Chemical Bonds

3b)What is the electronegativity trend across the period? Explain your reasoning.

4a)How do you define chemical bonding?

4b)Why do atoms want to form bonds?

4c)What types of chemical bonds exist and how are they defined?

5a) What is an Isoelectronic series? What is unique to members of the series?

5b) Give 3 examples of isoelectronic series

6a) What is a Lewis structure?

6b)Draw the Lewis dot structure for a neutral calcium atom.

6c)Draw the Lewis dot structure for a neutral oxygen atom

6d)Draw the Lewis dot structure for calcium oxide

7a) What is lattice energy? Why is it important?

7b)How much energy is involved by bringing together a calcium ion and an oxygen ion? Draw the  energy diagram and calculate the lattice energy for CaO.

7b)What is the lattice energy of MgF2? (Problem #62 in Ch. 3 of the book p. 150c) Draw the energy  diagram.

8a)What is a covalent bond?

8b) What are the types of covalent bonds. Describe each and give an example.

9) Refer to the energy information (text: page 105) on the hydrogen molecule to answer the  following:

9a) Describe what is happening when the nuclei are close to each other.

9b) Describe what is happening when the nuclei are far apart.

9c)Why does an energy well exist in the graph for hydrogen molecule? What does this tell us about  the molecule?

9d)What properties determine if atoms will combine to form covalent bonds?

10a)How many valence electrons do most atoms want to have in order to be stable?

10b)What are the exceptions? Why do they exist? Give examples

11a)How is the relative energy of associated covalent compounds calculated?

11b)Determine the energy associated with the formation of nitrogen trichloride from its elements, reaction shown below. Hint: N2 IS N-N, CI2 is CI-CI, and NCI3 IS three N-CI bonds. N2 (g) + 3Cl2 (g)    2NCI3 (I)

12) Determine the energy associated with the combustion of glucose, reaction shown below:   Hint:    H       CO2 IOOks like O=C=O.
H-  C-  O-  H

H / H
H  0   H  H     + 6 O2(g)—+6 CO2(g) + 6 H2O(g)
H   0 — H

13)Compare and contrast non-polar (purely covalent bonds) and polar covalent bonds.

14)Are the bonds in the molecules shown below non-polar, polar or ionic? Name each of the compounds

a) CO2

b) CH4

c) MgO

d) AsCI5

e) PH3

f) SO2

g) SiH4

h) Be3P2

i) ASI5

j) H2S

15) Compare and contrast the properties of ionic compounds with covalent molecules. Make a table of  comparison.

16a)OutIine the steps for drawing a Lewis structure for a molecule or ion.

16b) What is formal charge? How is it calculated? Why is its significance?

17)What atoms do not obey the octet rule? Why?

18) Draw the Lewis structures of the following molecules and calculate the formal charqe for each  atom in the compound as well as the molecule's overall formal charge:
18a) Carbon monoxide Lewis structure.Calculation Formal Charge for each atom.Calculation Formal Charge for molecule

18b) Ammonium ion Lewis structure.Calculation Formal Charge for each atom.Calculation Formal Charge for molecule

18c) Cyanide ion Lewis structure.Calculation Formal Charge for each atom.Calculation Formal Charge for molecule

18d) Phosphate ion Lewis structure .Calculation Formal Charge for each atom