1. Use average bond energies to calculate ΔHr for the combustion of ethanol. 

CH3CH2OH(g)+3O2(g)→2CO2(g)+3H2O(g)

Express your answer using four significant figures.

Answer: ΔHr=___kJ/mol

2.Cl3PO
Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons.

3.SeO2
Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons. Show the formal charges of all atoms in the correct structure. To change the symbol of an atom, double-click on the atom and enter the letter of the new atom.

4. Determine the number of bonding electrons and the number of nonbonding electrons in the structure of SiO2.
Enter the number of bonding electrons followed by the number of nonbonding electrons in the dot structure of this molecule separated by a comma (e.g., 1,2).

5. Draw the main Lewis structure of NOF.
Draw nonbonding electrons using the dot notation and bonding electrons as a bond.

6. Determine the number of bonding electrons and the number of nonbonding electrons in the structure of SI2.

Enter the number of bonding electrons followed by the number of nonbonding electrons, separated by a comma, in the dot structure of this molecule (e.g.,  1,2). 
7. Add single electron dots and/or pairs of dots as appropriate to show the Lewis symbols of the following neutral atoms.
Place electron dots as needed on each atom. Click either the single electron or lone pair buttons to add electrons.As, Se, Br, K, Ca, Ga