1. 2. Which of these is an example of a covalent compound?
Week9 1. The reaction for photosynthesis is 6CO2 + 6H2O  C6H12O6 + 6O2. How many oxygen atoms, O, are released for every 1 glucose, C6H12O6 , produced?
1 c. 6
2 d. 12
2. Which of these is an example of a covalent compound?
Sodium monochloride
Trimagnesium dinitride
Calcium chloride
Sulfur dioxide

2. 3. The formula for dinitrogen tetraoxide is
N3O3 NO
N2O2
N2O4
4. Which of the following is a characteristic of an ionic bond?
Low melting point
Shares electrons
Good conductor of electricity in aqueous solutions
Insoluble

3. 5. Complete the following reaction.
NaOH (aq) + HCl (aq)  ______ + H2O (l)
2NaCl (s)
NaCl (g)
NaCl (aq)
2NaCl (aq)
6. Which of the following is a true statement?
Matter is conserved in a chemical reaction.
Matter is created in a chemical reaction.
Matter is destroyed in a chemical reaction.
All of the above statements can be true depending on the reaction.

4. 7. Which of the following involves a chemical change?
Snow melting into water
An apple rotting on a tree
Boiling water until vapor forms
Making sweet iced tea
8. In chemistry class, Mr. V added some sodium to a beaker of water. The sodium reacts violently with the water, producing a flame. The end products are hydrogen gas and sodium hydroxide. Which of the following is the correct balanced equation for the reaction described above?
2 Na + 2 H2O  2 NaOH + H2
Na + H2O + O2  3 NaOH + H2
H2O2 + 2Na  2 NaOH + H2
2 NaOH + H2  2 Na + 2 H2O

5. 9. The following reaction is propane burning in oxygen to produce carbon dioxide and steam. __C3H8 + __O2  __CO2 + __H2O Which of the following sets of numbers will balance this equation?
1, 5, 3, 4
1, 3, 4, 5
5, 4, 3, 1
4, 5, 1, 3

6. 10. The electrolysis of water is performed by passing an electric current through water to break the chemical bonds that hold it together. What kind of reaction is this? 2 H2O  2H2 + O2
Synthesis
Decomposition
Single replacement
Double replacement