Convert the following:

1.    6.1 x 10-2 m to Gm                                                                       2.    0.023 L to μL

6.1 x 10-2 m |    1    Gm = 6.1 x 10-11 Gm                               0.023 L |      1     μL = 23000 μL or 2.3 x 104 μL
                       | 1 x 109 m                                                                   | 1 x 10-6 L

3.      2.37 x 10-5 mg to g                                                                      4.    3.94 x 107 cm3 to L

2.37 x 10-5 mg | 1 x 10-3 g = 2.37 x 10-8 g                            3.94 x 107 mL | 1 x 10-3 L = 39400 L / 3.94 x 104 L
                            |     1 mg                                                                                |     1 mL

5.    9.46 x 109 kg to g                                                                          6.    4.88 x 10-4 dm3 to mL
9.46 x 109 kg | 1 x 103 g = 9.46 x 1012 g                               4.88 x 10-4 L |    1    mL = 0.488 mL
                         |    1    kg                                                                                                | 1 x 10-3 L

 

How many significant figures are in each of these measurements?

1.    104 g               3                                              2.    104.01 g                         5

3.    40 g 1                                                              4.    40. g                                2

5.    140.0 g           4                                              6.    0.0140 g                         3

7.    4.10 x 103 g    3                                              8.    2.003 x 10-5 g                4

Round each number to the specified number of significant figures.

1.    14.989                          4 SFs   14.99                       3 SFs   15.0                         2 SFs   15 

2.    31,011                          4 SFs 31,010                      3 SFs 3.10 x 104                2 SFs   31,000 

 

Calculate the following using the appropriate number of significant figures in your answer.

1.    What is the volume of a shoebox whose dimensions are 125 cm by 25.5 cm by 30.0 cm?

                V = l x w x h                        V = 125 cm x 25.5 cm x 30.0 cm = 95625 cm3  round to 95600 cm3

2.    A woman has a purse weighing 954.4 g.  A 121.23 g cell phone and an 11.29 g tube of lipstick were

        stolen from it!  How much does the purse weigh now?

                954.4 g – 121.23 g – 11.29 g = 821.88 g  round to 821.9 g

3.    A graduated cylinder is places on an electronic balance and it reads 81.19 g.  After 15.5 mL  of

        acetone were added, the balance reads 95.33 g.  What is the density of acetone?
               
95.33 g – 81.19 g =   14.14 g   = 0.912 g/mL
                                                          15.5 mL

4.    Mystery object A has a density of 3.90 g/mL.  If it weighs 450 g, what is its volume?

                3.90 g/mL =  450 g         V = 115.3846154 mL  round to 120 mL
                                           V

5.    Marisa determined the melting point of a substance to be 24.5oC.  Find the percent error of her

        measurement if the actual melting point is 31.2oC.

                |31.2oC – 24.5oC| x 100 = 21.5% or 21%
                          31.2oC

6.      What is the mass of a 35.5 cm3 sample of zinc?  (The density of zinc is 7.14 g/cm3.)

           7.14 g/cm3 =        m                         m = 253 g
                                    35.5 cm3

7.       The molar mass of butane is 58.14 g/mole.  Using his lab data, Tyrone calculated the molar mass  
     of butane as 44.21 g/mole.  Find the percent error of his measurement.

          
|55.14 – 44.21| x 100 = 23.96%
                  55.14

 

Identify each of the following changes as physical (P), chemical (C), or a nuclear (N).

P1.    You cut your hair.

P2.    Making a peanut, pretzel and cereal mixture.

C3.    Baking soda reacts with vinegar and forms a gas.

P4.    A piece of metal is bent in half.

P5.    An aspirin is crushed into fine powder.

C6.    Copper turns green when exposed to the environment.

N7.    Fission of uranium into xenon and strontium.

C8.    Baking cookies.

P9.    Diamonds are used to scratch glass.

C10.    A tree burns to form ashes.

P11.    A piece of paper is crumpled up.

P12.    Water freezes to form ice.

C13.    Food spoiling.

C14.    A candle burning.

P15.    A candle melting.

N16.   Fusion of hydrogen atoms into helium.

P17.    Salt dissolves in water.

C18.    Hydrochloric acid reacts with magnesium to produce hydrogen gas.

P19.    A piece of copper is cut in half.

P20.    A sugar cube is ground up.

P21.    Ethyl alcohol evaporates.

P22.    Ethyl alcohol boils at 79°C.

C23.    Paper burns.

C24.    Fireworks explode.

C25.    Alka-Seltzer gives off carbon dioxide when added to water.

 

Determine if each of the following is a mixture or a pure substance.  If it is a mixture, identify if the mixture is homogeneous or heterogeneous.  If it is a pure substance, identify if the substance is an element or a compound.

1.    Sugar (C12H22O11)          PS - C                      2.    Liquid nitrogen PS - E                                 3.    Apple juice M - HO

4.      Ocean water M - HO                                   5.    Methane gas (CH4) PS - C                            6.    Gasoline M - HO

7.      Coffee M - HO                                              8.    Lucky Charms® cereal M - HE                 9.    Wood M - HE

10.       Pencil M - HE                                            11.    Hot fudge sundae M - HE                         12.    Silver PS - E

13.    Pepperoni Pizza M - HE                           14.    Mercury PS - E                                           15.    Big Mac® M - HE

 

Locate these areas on the Periodic Table.

1.      Halogens                                                       2.    Lanthanide Series                                                        3.    Noble Gases

4.      Alkaline Earth Metals                                5.    Transition Metals                                                        6.    Alkali Metals

7.      Inner Transition Metals                            8.    Actinide Series                                                             9.    Metalloids