Download Chemistry Section Review 2.3

Chemistry Section Review 2.3
Multiple Choice
Identify the choice that best completes the statement or answers the question.
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1. A measurement that closely agrees with accepted values is said to be
a. precise.
c. significant.
b. reliable.
d. accurate.
2. A measurement is said to have good precision if it
a. agrees closely with an accepted standard.
b. agrees closely with other measurements of the same quantity.
c. has a small number of significant figures.
d. has a large number of significant figures.
3. Poor precision in scientific measurement may arise from
a. the standard being too strict.
b. human error.
c. limitations of the measuring instrument.
d. both human error and the limitations of the measuring instrument.
4. These values were obtained as the mass of products from the same reaction: 8.83 g; 8.84 g; 8.82 g. The
known mass of products from that reaction is 8.60 g. The values are
a. accurate.
c. both accurate and precise.
b. precise.
d. neither accurate nor precise.
5. A chemist who frequently carries out a complex experiment is likely to have high
a. accuracy, but low precision.
c. precision.
b. accuracy.
d. precision, but low accuracy.
Mass Data of Sample
Trial 1 Trial 2 Trial 3
Trial 4
Student A
1.43 g
1.52 g
1.47 g
1.42 g
Student B
1.43 g
1.40 g
1.46 g
1.44 g
Student C
1.54 g
1.56 g
1.58 g
1.50 g
Student D
0.86 g
1.24 g
1.52 g
1.42 g
6. Four students each measured the mass of one 1.43 g sample four times. The results in the table above indicate
that the data collected by ____ reflect the greatest accuracy and precision.
a. Student A
c. Student C
b. Student B
d. Student D
7. For numbers less than 0.1, such as 0.06, the zeros to the right of the decimal point but before the first nonzero
digit
a. are significant.
b. show the decimal place of the first digit.
c. show that the zero on the left side of the decimal is not significant.
d. show uncertainty.
8. To two significant figures, the measurement 0.0255 g should be reported as
a. 0.02 g.
c. 0.026 g.
b. 0.025 g.
d. 2.5  102 g.
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9. A sum or difference of whole numbers should be rounded so that the final digit is in the same place as the
a. rightmost uncertain digit.
c. leftmost uncertain digit.
b. last digit in the longest number.
d. leftmost certain digit.
10. The number of significant figures in the measured value 0.003 20 g is
a. 2.
c. 5.
b. 3.
d. 6.
11. The measurement that has been expressed to three significant figures is
a. 0.052 g.
c. 3.065 g.
b. 0.202 g.
d. 5000 g.
12. The number of significant figures in the measurement 210 cm is
a. 1.
c. 3.
b. 2.
d. 4.
13. The measurement that has only nonsignificant zeros is
a. 0.0037 mL.
c. 400. mL.
b. 60.0 mL.
d. 506 mL.
14. The dimensions of a rectangular solid are measured to be 1.27 cm, 1.3 cm, and 2.5 cm. The volume should be
recorded as
a. 4.128 cm3.
c. 4.13 cm3.
b. 4.12 cm3.
d. 4.1 cm3.
15. Three samples of 0.12 g, 1.8 g, and 0.562 g are mixed together. The combined mass of all three samples,
expressed to the correct number of significant figures, should be recorded as
a. 2.4 g.
c. 2.482 g.
b. 2.48 g.
d. 2.5 g.
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16. Round 1.245 633 501  10 to four significant figures.
a. 1246
c. 1.246  108
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b. 1.2456  10
d. 1.246  104
17. The correct number of significant figures that should appear in the answer to the calculation 3.475  1.97 +
2.4712 is
a. 2.
c. 4.
b. 3.
d. 5.
18. The measurement 0.020 L is the same as
a. 2.0  10–3 L.
c. 2.0  10–2 L.
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b. 2.0  10 L.
d. 2.0  10–1 L.
19. The speed of light is 300 000 km/s. In scientific notation, this speed is
a. 3  105 km/s.
c. 3.0  106 km/s.
b. 3.00  105 km/s.
d. 3.00  106 km/s.
20. The average distance between the Earth and the moon is 386 000 km. Expressed in scientific notation, this
distance is
a. 386  103 km.
c. 3.8  105 km.
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b. 38  10 km.
d. 3.86  105 km.
21. Two variables are directly proportional if their ____ has a constant value.
a. sum
c. quotient
b. difference
d. product
22. The graph of a direct proportion is a(n)
a. straight line.
c. parabola.
b. ellipse.
d. hyperbola.
23. Two variables are inversely proportional if their ____ has a constant value.
a. sum
c. product
b. difference
d. quotient
____ 24. In the expression m = DV, where m is mass, D is density, and V is volume, density is the
a. variable.
c. constant.
b. difference of m and V.
d. product of m and V.
____ 25. In the equation density = mass/volume, mass divided by volume has a constant ratio. This means that the
a. equation graphs as a straight line.
b. variables mass and volume are inversely proportional.
c. equation graphs as a hyperbola.
d. product of mass and volume is a constant.