Practice final exam

1.      Draw the electron configuration for

Al                                                                    

2.      Draw the electron dot structure for

Silicon____________        Bromine______________

3.      What type of bond exists between the following pairs of elements? Write Ionic or covalent.

Br and O_____________    Na and S_____________  C and Cl______________

4.      Name the following ionic compounds.

NaNO₃_____________________            NH₄Br____________________

5.      Write the formula for the following ionic compounds.

Sodium sulfate______________________      Silver Oxide___________________

6.      Classify the following chemical reactions into one of the  five types learned in class. (6 points)

KCl_(aq + AgNO_3(aq à AgCl _(s) +  KNO₃                          _______________________

2HCl_(aq + Zn _(s) à H_{2 (g)}  +  ZnCl_{2 (aq)}                                               _______________________

CH_4(g)   +  2O_{2 (g)}  à CO_{2 C} +   2H₂O _(g)                                               _______________________

H₂O _(g)  +  CO_{2 (g)}  à  H₂CO_3(aq)                                                                            _______________________

                        _D

2KClO₃ à 3O_{2 (g)} + 2KCl _(s)                                                          _______________________

Na_(s) + H₂O_(l) à NaOH_(aq)  + H_{2 (g)}                                         ______________________

7.      What is the percent composition of water H₂O?  Use the periodic table to find the atomic masses of hydrogen and oxygen to use in your calculation. (4p points)

8.      What are 2 differences between heat and temperature?  (4 points)

9.      A student burns a walnut that has a mass of 9 g under a beaker containing 100 ml of water.  The water’s temperature goes from 20 ^oC to 88 ^oC.  How many calories did the water gain? (6 points)

10.  What are three ways to make a solid solute dissolve more quickly into solution?

(3 points)

a. 

b.

c.

11.  Do gases become more or less soluble when the solution is heated? (1 point)

12.  What is the difference between a solution and a suspension? (3 points)

13.  What are the 2 parts of a solution?  (2Points)

a.

b.

A student puts a crystal of solute into a solution.  The crystal floats to the bottom and does not dissolve.  Is the solution saturated, unsaturated or supersaturated? (1 point)

points                                           

14.  State if the following are compounds mixtures or elements.(4 points)

15.  Give two observations that would indicate a chemical change. (2 points)

16.  Indicate if the following is a chemical or physical change (4 points)

Complete  the following problems.  Show all work and correct units.

1.       (4 points) An object has a mass of 22.35 g and a volume of 42.19 ml.  What is its density?

Will the object float or sink when put into water? (Hint:  the density of water is 1 g/ml)

2.       (6 points) To measure the mass of a small rock a student places it on a balance, and the balance reads 48.3 g.  To measure the rock’s volume the student gets a graduated cylinder.  She then puts 25 ml into the graduated cylinder.  Next, she gently slides the rock into the cylinder and the water level goes up to 46 ml.  What is the density of the rock?

Complete  the following problems.  Show all work and correct units.

3.       How many ml are in 25.67 L? (3points)

4.       There are 2.54 cm in one inch.  How many inches is 65.8 cm? (3points)

5.       Which is larger an ounce or a gram? (1point)

6.       Which is larger a yard or a meter? (1point)

7.       Just before lighting a burner should the air hole be open or closed? (1point)

8.       What is the purpose of deionized water? (1point)