simple chemistry problems worksheet

Chapter 2 Homework

Please complete all questions on a separate piece of paper. For questions that require calculations show ALL steps and box all of the answers for full credit.

# Questions

1. Define the different types of zeros found in a number and explain whether or not they are significant.

1. Give the two conversion factors you can construct using each pair of units.

c) meters and kilometers

b) liters and microliters

a) seconds and milliseconds

1. In general, how can you identify whether or not you have written the correct conversion factor for the problem?

1. Construct a conversion factor that can convert from one unit to the other in each pair of units.
1. meter to km
2. inch to cm
3. pounds to kilogram

# Scientific Notation

1. Convert each number into scientific notation
1. 736,350
2. 0.0042
3. 2500
4. 0.478
2. Convert each number into decimal notation a. 7.42 x 103
1. 1.3 x 10-3
2. 1.5 x 106
3. 1.5147 x 10-5

1. Fill in the blank
 Scientific Notation Decimal Notation a) 4.7 x103 b) 7,410. c) 9.3 x 10-4 d) 0.0045

# Significant Figures

8) Use each diagram to report a measurement to the proper number of significant figures. a) b) c)

d)  9)

a) b) c) d) 10) Give the number of significant figures in each. Identify the rule for each. a) 0.000140500 s

1. 630,001 kg
2. 155.000 in
3. 0.0745 m

1. How many significant figures are in each number?
1. 1.05
2. 9,500
3. 0.0004505
4. 7563

1. How many significant figures are in each number? a. 0.052010
1. 0.3940
2. 8200
3. 8563

# Rounding

1. Round each number to three significant figures.
1. 24.632
2. 0.34244
3. 43,539
4. 6.9978 x 106

1. Determine if each number is rounded correctly to three significant figures. For the one that is incorrect, correct them
1. 3.459 x 103 to 3.5 x 103
2. 4.874 x 103 to 50
3. 87.42 to 87.4
4. 0.09853 to 0.010

1. Complete the table
 Number Rounded to 4Significant Figures Rounded to 2Significant Figures Rounded to 1Significant Figures a. 53.53229 53.53 54 5 x 101 b.216.3535 c. 0.36682 d. 0.00888881

# Significant Figures in Calculations

1. Determine if each calculation has the correct number of significant figures. For the one that is incorrect, correct them
1. 105.34 x 47.334532 = 4986.22
2. 0.047 x 23.3544 = 1.098
3. 5.5225 / 503.455 = 0.010969
4. 0.000154*1002.2 = 0.15

1. Determine if each calculation has the correct number of significant figures. For the one that is incorrect, correct them
2. 5.8 + 63.09 – 14 = 54.9
3. 4301 – 2900.14 + 1.6 = 1402
4. 0.00354 + 0.86 = 0.863
5. 0.00974 – 0.008 = 0.00074

18) Determine if each calculation has the correct number of significant figures. For the one that is incorrect, correct them

1. 3.5 + 94.04 – 50 = 47.5
2. 8206 – 5614.25 + 5.5 = 2597.25
3. 0.00354 + 0.864 = 0.868
4. 0.01874 – 0.010 = 0.00874

19) Determine if each calculation has the correct number of significant figures. For the one that is incorrect, correct them

1. (9.95 + 3.09) / 7.40000 = 1.762
2. (1045.3 – 1.4) x 1.604 = 1674
3. (749.40 + 6.7) / 4.54 = 1.6 x 102
4. (845 / 301457) + 5.000198 = 5.00

# Unit Conversion

20) Convert the following metric quantities into the indicated units. Identify the number of significant figures in each answer. a. 1000. g into milligram

1. 6981 nm into meter
2. 15 mL into liter

d) 345 cm to millimeters

21) Use English-to-Metric and Metric-to-English conversion factors to calculate the following: a) 87.6 ft into centimeter

1. 557 yd to meters
2. 645 feet to centimeter
3. 7.0 inch to cm

22) Use English-to-Metric and Metric-to-English conversion factors to calculate the following: a) 90.7 ft into millimeter

1. 14.8 lbs to kg
2. 400. m to mi
3. 12.0 inch to cm

23) Fill in the blank to complete the table

 m km mm nm pm 6.02 x10-5 s 6.02 x 10-2 mm 25.3 pm 225 nm 8.22 x 10-3 km 4.2 x 105 mm

Unit Raised to a Power 24) Perform each conversion a) 1.2 ft2 = _____in2

1. 1.2 yd2 = _______ft2
2. 1.2 m3 = _______ yd3

25) Perform each conversion a) 3.5 ft2 = _____in2

1. 3.5 yd2 = _______ft2
2. 35 m3 = _______ yd3

26) A pizza has an area of 3.44 m2. Perform a conversion to each of the following units. a) in2

1. mm2
2. km2

# Density

1. A copper strip has a mass of 4.67 gram and volume of 0.523 cm3. What is the density of the copper strip? Is the strip pure copper?

1. A silver ingot has a mass of 70.34 gram and volume of 8.5 cm3. What is the density of the ingot? Is the ingot pure silver?

1. Given the density of Gold is 19.3 g/cm3
2. Determine the mass of gold (in grams) in an ingot with the volume of 121 cm3
3. Determine the volume of gold (in cm3) in an ingot with the mass of 1354 gram

30) Given the density of Cu is 8.93 g/cm3

1. Determine the mass of copper (in gram) in a copper strip with the volume of 433.0 cm3.
2. Determine the volume of copper (in cm3) in a copper strip with the mass of 502.34 gram.

31) Given the density of lead is 11.34 g/cm3

1. Determine the mass of lead (in gram) in a lead block with the volume of 607.9 cm3.
2. Determine the volume of lead (in cm3) in a lead block with the mass of 802.35 gram.

# Cumulative Problems

1. If the walls in a room are 955 square feet in area, and a gallon of paint covers 15 square yards, how many gallons of paint are needed for the room? (3 ft = 1 yd)

1. If an object has a density of 8.65 g/cm3, what is its density in units of kg/m3?

Chapter 2

1. Water is being pumped out of a reservoir at a rate of 2.54 liters per 15.0 seconds. If the reservoir contains 1.0500 x 106 gallons of water, how many hours will it take to empty it?

1. The mass of an average blueberry is 0.75 g and the mass of an automobile is 2.0103 kg. Find the number of automobiles whose total mass is the same as 1.0 x 1010 blueberries?

1. Tom and Mary both have farms. Tom raises chicken for eggs while Mary plants apple. Tree pounds of apple can be exchanged with 1 dozen of eggs. If Tom has 130. eggs to exchange with Mary, how many pounds of apple will he get?

1. Calculate the number of seconds in 1.00 year.