First Name Section M W EXAM 1 REVIEW: READING AND RECORDING DATA SIGNIFICANT FIGURES AND UNCERTAINTY

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1 Last Name Due Date First Name Section M W : READING AND RECORDING DATA SIGNIFICANT FIGURES AND UNCERTAINTY General Information Max Time: Try to do these problems faster than the Max Time. If you do all of the problems in exactly Max Time, you will not finish the exam. Based upon the following pictures, write what you would record in your laboratory notebook. Also write the uncertainty value that should be recorded. 1) The piece of equipment above is called a buret. WOTF (Which of the following) is the best correctly written measurement to record in a lab notebook? Assume that the student was not required to record uncertainty. A) 21.1 ml B) ml C) 22.8 ml D) ml E) 22.9 ml 2) The piece of equipment above is called a buret. WOTF (Which of the following) is the correct uncertainty value to record? Page 1 of 6

2 3) The piece of equipment above is a partially-filled buret. WOTF (Which of the following) is the best correctly written measurement to record in a lab notebook? Assume that the student was not required to record uncertainty. A) 40 ml B) 40. ml C) ml D) ml E) ml 4) The piece of equipment above is a partially-filled buret. WOTF (Which of the following) is the correct uncertainty value to record? 5) The piece of equipment above is a partially-filled 100-mL graduated cylinder. WOTF (Which of the following) is the best correctly written measurement to record in a lab notebook? Assume that the student was not required to record uncertainty. A) 50 ml B) 50. ml C) 52.9 ml D) 53 ml E) 53.0 ml 6) The piece of equipment above is a partially-filled 100-mL graduated cylinder. WOTF (Which of the following) is the correct uncertainty value to record? Page 2 of 6

3 7) The piece of equipment above is a partially-filled 10-mL graduated cylinder. WOTF (Which of the following) is the best correctly written measurement to record in a lab notebook? Assume that the student was not required to record uncertainty. A) 6 ml B) 6.3 ml C) 6.30 ml D) 7.7 ml E) 7.70 ml 8) The piece of equipment above is a partially-filled 10-mL graduated cylinder. WOTF (Which of the following) is the correct uncertainty value to record? 9) The piece of equipment above is the display of an electronic balance. WOTF (Which of the following) is the best correctly written measurement to record in a lab notebook? Assume that the student was not required to record uncertainty. A) 6 g B) 5.9 g C) 5.91 g D) g E) g 10) The piece of equipment above is the display of an electronic balance. WOTF (Which of the following) is the correct uncertainty value to record? A) ± g B) ± g C) ± 0.01 g D) ± 0.1 g E) ± 1 g Page 3 of 6

4 11) The piece of equipment above is a centimeter ruler (millimeter-scale). WOTF (Which of the following) is the best correctly written measurement to record in a lab notebook? Assume that the student was not required to record uncertainty. A) 5 cm B) 5.3 cm C) 5.30 cm D) 5.31 cm E) 6 cm 12) The piece of equipment above is a partially-filled 10-mL graduated cylinder. WOTF (Which of the following) is the correct uncertainty value to record? A) ± cm B) ± cm C) ± 0.01 cm D) ± 0.05 cm E) ± 0.1 cm Page 4 of 6

5 13) The piece of equipment above is a centimeter ruler (centimeter-scale). WOTF (Which of the following) is the best correctly written measurement to record in a lab notebook? Assume that the student was not required to record uncertainty. A) 6 cm B) 6.3 cm C) 6.30 cm D) 6.5 cm E) 6.50 cm 14) The piece of equipment above is a centimeter ruler (centimeter-scale). WOTF (Which of the following) is the correct uncertainty value to record? A) ± cm B) ± cm C) ± 0.01 cm D) ± 0.05 cm E) ± 0.1 cm Page 5 of 6

6 Answers 1) B. Remember that burets are read from the top towards the bottom. The most precise marking on the buret is the tenths (0.0 ml) place, so you must estimate the hundredths place (0.00 ml). Also, remember that when the markings are very close to each other, the last digit should be a 0 or a 5 2) B. Since you are estimating the hundredths place, the uncertainty must be in the hundredths place, as well. Also, remember that when the markings are very close to each other, the last digit should be a 0 or a 5. 3) C 4) B 5) E 6) D 7) C 8) B 9) E. For an electronic balance, don t ever round. Write down exactly what you see! 10) A. The last digit on the electronic balance is always the estimated digit to within ± 1 11) C. The most precise reading is the tenths place, so you must estimate the hundredths place. Since the markings are very close to each other, the last digit can only be a 0 or a 5. 12) D 13) B. The most precise markings on the ruler is the ones place. So, you must estimate the tenths place. Since the markings are far apart from each other, the last digit can be any digit from 0 to 9. 14) E Page 6 of 6