Lab 1.3 w/s #1Name______Period____

Significant Digits Practice

Determine the number of significant digits in each of the following:

Put an N under each zero that is not significant

1) 4,5003) .008005) 7.07) 703

2) 10804) 102,0056) 0.0040508) 0.0023

Add and report the sum to the appropriate number of significant figures:

9) 124.5g + .785g =11) 36.8km + 3.289km + 217.0009km =

10) 25m + 0.084m + 8.995m =12) 5.95kg + 3.0007kg + .00135kg =

Subtract and report the difference the appropriate number of significant figures:

13) 157.085 g - 9.2 g = 14) 487 ml - 4.097 ml

15) 150 – 13.98 =15) 2.0 – 1.00056 =

Multiply and report the product to the appropriate number of significant figures:

17) 4.0 cm x 5.351 cm. =18) 5.012 g x 3.14 g. =

19) 150 x 23.58 = 20) 0.137 x 0.4 =

Divide and report the quotient to the appropriate number of significant figures

21) 29.3 g ÷ 1.7 ml. =22) 330.06 mm ÷ 6.2 mm =

23) 2.008 ÷ .004 =24) 9,500 ÷ 257.3 =

Solve each of the following problems involving errors of measurement

25) A student measures the density of mercury as 11.9 g/ml. The established density of mercury is 13.55 g/ml. What is the percent error?

26) Measurements of the melting point of aluminum indicate a melting point of 603 ˚C. The accepted value of the melting point is 659˚C. Calculate the percent error.

27) Consider the data collected by two students.

student A / calculate / student B / calculate
66.9˚C
70.0˚C
68.2˚C / average measured value
calculate percent error / 45.2˚C
44.8˚C
45.0˚C / average measured value
calculate percent error
actual value
68.0˚C / actual value
47.0˚C

Include deviation from the average or percent error in your explanation.

Which student’s data is more precise? Explain your reasoning.

Which student’s data is more accurate? Explain your reasoning.

Lab 1.3 w/s #2Name______Period____

Scientific Notation Practice

Express the following using scientific notation:

1) 20,000,0006) .062

2) .000017) 55,000,000

3) 437,0008) .00000029

4) .00007839) .03

5) 76,45010) 4,670,000,000

Express the following in standard form:

11) 3.5 x 10-316) 7.53 x 108

12) 4 x 10517) 3.0 x 10-6

13) 2.3 x 10718) 4.6 x 10-11

14) 6.00 x 10-419) 8 x 109

15) 8.01 x 10-620) 3.4 x 10-2

Calculations involving measurement errors:

21) The yield predicted in a particular reaction is 0.132 g. The actual yield obtained by a chemist in a specific experiment is 0.098 grams. Calculate the percent error.

22) A person weighs at home and then shortly thereafter at the doctor's office. At home, he weighs 175 pounds, but at the doctor's office on a more accurate scale he weighs 178 pounds. What is the percent error between the readings?

23) Precision or accuracy

Repeating the experiment many times and getting the close to the same results. Does this indicate accuracy or precision? Explain.

Measurements with a low percent error. Does this indicate accuracy or precision? Explain.

Close too "correct". Does this indicate accuracy or precision? Explain.

Small range in results of measurement. Each measurement is close to the average. Does this indicate accuracy or precision? Explain.

Lab 1.3 w/s #3Name______Period____

Additional Significant Digits Practice

Determine the number of significant digits in each of the following:

For each zero, indicate whether it is significant (draw an arrow to it) or not significant (write N beneath it). State why it is either significant or not.

3,080,0003.006700.00000406007

Calculations with significant digits. Use scientific notation where appropriate.

4.05 + 67.875 + 303 = 70600 x 4.8 =

67.24 g ÷ 22 ml. =6070 - 357.9 =

Express the following using scientific notation:

1) 356,000 6) .0057

2) .000847) 300,000

3) 32,000,000,0008) .00000000470

Express the following in standard form:

11) 8.4 x 10-416) 7.1 x 10-5

12) 3.29 x 10717) 4.356 x 108

13) 5.83 x 10918) 6 x 10-4

Explain precision. Cite examples to show both precise and not precise measurements.

Explain accuracy. Explain how percent error calculations reflect the degree of accuracy.

Explain exactness and how significant figures reflect the exactness of measurement.