1,001 Chemistry Practice Problems For Dummies (2014)

Part I. The Questions

Chapter 15. Graphing Basics

Graphs are a visual means of summarizing data. A good graph gives more information than a simple table of x and y values. Bad graphs can be very misleading. Scientists need to be able to transmit information in the form of good graphs.

The Problems You’ll Work On

In this chapter, you work with graphing basics in the following ways:

check Identifying parts of a graph

check Determining graph scales

check Drawing and interpreting graphs

check Predicting values

What to Watch Out For

Remember the following when working on graphing:

check Very few graphs simply connect the data points.

check The more neatly a graph is drawn, the easier it is to read.

check The graph should occupy most, if not all, of the space available.

check The scales should place the highest values near the top or right of the graph. The lowest values should appear near the bottom or left of the graph.

Graphing

981–1,001 Answer the following questions on graphing. When data appears in a two-column format, the first column contains the data for the x-axis, and the second column contains the data for the y-axis. You can sketch the graphs by hand or use a program such as Excel.

981. What is the name of the position on the graph denoted by x = 0 and y = 0?

982. What do you call the process of finding a value on a graph that falls within the range of the plotted points?

983. What do you call the process of estimating a value on a graph that falls outside the range of the plotted points?

984. A plot of mass (y-axis) versus volume (x-axis) gives you a straight-line plot. What does the intercept of this line with the x-axis represent?

985. A plot of volume (y-axis) versus temperature (x-axis) gives you a straight-line plot. What does the intercept of this line with the x-axis represent?

986. In a graph of distance versus time, what does the slope of the line represent?

987. In a graph of mass versus volume, what does the slope of the line represent?

988. In a graph of heat energy versus temperature, what does the slope of the line represent?

989. According to Charles’s law, the volume of an ideal gas is directly proportional to the temperature of the gas. What does a graph of volume versus temperature look like?

990. According to Boyle’s law, the pressure of an ideal gas is inversely proportional to the volume of the gas. What does a graph of volume versus pressure look like?

991. What does a graph of the volume (y-axis) versus the edge of a cube (x-axis) look like?

992. Graph the following data with a line of best fit. Use your graph to estimate how many pennies would be in a stack that has a mass of 84.1 g.

Number of Pennies

Mass (g)

5

15.2

10

31.5

15

46.2

20

60.4

25

77.3

30

91.7

993. In a graph depicting the following information, what does the slope of the line represent?

Number of Pennies

Mass (g)

5

15.2

10

31.5

15

46.2

20

60.4

25

77.3

30

91.7

994. Graph the following data with a line of best fit. Then use the graph to estimate the volume of 31.0 g of the substance.

Volume (mL)

Mass (g)

2.2

11.9

3.9

28.2

5.5

37.7

7.1

48.9

9.1

60.1

10.6

76.0

995. Graph the following data with a line of best fit. What is the mass of 10.0 mL of the substance?

Volume (mL)

Mass (g)

2.2

11.9

3.9

28.2

5.5

37.7

7.1

48.9

9.1

60.1

10.6

76.0

996. Graph the following data. Then use the graph to estimate the concentration at an absorbance of 0.318.

Concentration (M)

Absorbance

0.100

0.385

0.075

0.300

0.050

0.187

0.025

0.099

997. Graph the following data. Then use the graph to estimate the absorbance at a concentration of 0.125 M.

Concentration (M)

Absorbance

0.100

0.385

0.075

0.300

0.050

0.187

0.025

0.099

998. What is the x-intercept of the best-fit line for the graph of the following data? (Hint: The x-axis should go from –300°C to +200°C.)

Temperature (°C)

Volume (L)

0.0

1.00

50.0

1.18

100.0

1.37

150.0

1.55

999. Describe the shape of the graph of the following data.

Volume (mL)

pH

0.00

3.09

5.00

4.07

10.00

4.49

13.00

4.70

16.00

4.92

19.00

5.18

22.00

5.58

23.00

5.82

24.00

6.30

24.25

6.51

24.50

7.04

24.75

9.46

24.90

10.23

25.00

10.31

25.10

10.47

25.25

10.61

25.50

10.78

25.75

10.93

26.00

11.01

27.00

11.28

28.00

11.43

31.03

11.56

1,000. Graph the following data for the titration of a weak acid with a strong base. Then use the graph to estimate the pH at 12.25 mL.

Volume (mL)

pH

0.00

3.09

5.00

4.07

10.00

4.49

13.00

4.70

16.00

4.92

19.00

5.18

22.00

5.58

23.00

5.82

24.00

6.30

24.25

6.51

24.50

7.04

24.75

9.46

24.90

10.23

25.00

10.31

25.10

10.47

25.25

10.61

25.50

10.78

25.75

10.93

26.00

11.01

27.00

11.28

28.00

11.43

31.03

11.56

1,001. A student conducts a kinetic experiment for a second-order reaction. Graphing which two columns in the following table will produce a straight line?

Time (min)

[A] (M)

ln[A]

9781118549322-eq15001.eps

0

0.2000

–1.61

5.0

5

0.0282

–3.57

35.5

10

0.0156

–4.17

64.1

15

0.0106

–4.55

94.3

20

0.0080

–4.83

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