Question 1

Which of the following best describes a significant figure in a measured value?

Accepted Answer

All certain digits plus one final digit that has some uncertainty.

Question 2

A student measures the length of a pencil using two different rulers. Ruler A has divisions every 1 cm, and Ruler B has divisions every 0.1 cm. Which statement is correct regarding the uncertainty in the measurements?

Accepted Answer

The measurement with Ruler B will have less uncertainty because it allows estimation to a smaller division.

Question 3

Which of the following numbers contains exactly three significant figures?

Accepted Answer

$$0.00340$$

Question 4

When adding $$15.346$$ and $$2.70$$, what is the correct answer with the proper number of significant figures?

Accepted Answer

$$18.0$$

Question 5

Which of the following statements about zeros is correct?

Accepted Answer

Trailing zeros in a number without a decimal point may or may not be significant.

Question 6

A buret is used to measure $$10.00 mL of a $$solution. How many significant figures does this measurement have?

Accepted Answer

4

Question 7

You are asked to calculate the total volume when $$11.5 mL ($$measured with a graduated cylinder) is added to $$10.00 mL ($$measured with a buret). What is the correct way to report the sum?

Accepted Answer

$$21.5 mL$$

Question 8

Which of the following best explains why $$0.00560$$ has three significant figures?

Accepted Answer

Because the zeros after the 6 are trailing zeros after a decimal point and are significant.

Question 9

A student records a measurement as $$25.00 mL. $$Which statement is true about the uncertainty in this measurement?

Accepted Answer

The uncertainty is in the hundredths place.

Question 10

When multiplying $$3.15 	imes 10^3$ by 2.546$$ 	imes $$10^{-4}$$, how many significant figures should the answer have?

Accepted Answer

3

Question 11

Suppose you have an experimental value of molar mass $$12.82$$ and a theoretical value of $$12.5. $$What is the percent error, reported to the correct number of significant figures?

Accepted Answer

$$2.6\%$$

Question 12

Which of the following is an example of an exact number?

Accepted Answer

The number of students in a classroom.

Question 13

How many significant figures are in the number $$0.000509$$?

Accepted Answer

3

Question 14

Which of the following measurements is recorded with the correct number of significant figures if the smallest division on the measuring device is $$0.1 mL$$?

Accepted Answer

$$10.0 mL$$

Question 15

When dividing $$0.0654 by$$ $$0.000954$$, how many significant figures should the answer have?

Accepted Answer

4

Question 16

A student adds $$99.16$$ and $$26.85$$, then adds $$41.5. $$What is the correct way to report the final sum?

Accepted Answer

$$167.5$$

Question 17

Which of the following best describes the rule for significant figures in addition and subtraction?

Accepted Answer

The answer should have as many decimal places as the measurement with the fewest decimal places.

Question 18

Which of the following numbers has four significant figures?

Accepted Answer

$$0.05340$$

Question 19

A student calculates $$(6.543 - 6.4790)$$ using a calculator and gets $$0.064. $$How should the answer be reported with the correct number of significant figures?

Accepted Answer

$$0.06$$

Question 20

Which of the following best explains why leading zeros are not significant?

Accepted Answer

They are only placeholders and do not represent measured values.

Measurement, Uncertainty, and Significant Figures in General Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard