Q: A hydrogen atom has a volume of approximately $$6.2 \times 10$$^{-31}$$ m^3$. Which of the following is the correct way to express this in cubic centimeters?

$$6.2 \times 10$$^{-25}$$ cm^3$

Q: Which of the following is the correct way to convert $$5.08 \times 10$$^{2}$$ miles to kilometers, given that 1$ mile = 1.61$ km?

$$5.08 \times 10$$^{2}$$ \times 1.61 = 8.18 \times 10$$^{2}$$ km$

Question 1

Which of the following best explains why it is important to use scientific notation when reporting very large or very small numbers in chemistry?

Accepted Answer

It makes numbers easier to compare and reduces the risk of calculation errors.

Question 2

A laboratory balance displays a mass as 0.0300 g. How many significant figures are in this measurement?

Accepted Answer

$$4$$

Question 3

Convert $$2.54$$ inches to centimeters, given that $$1$$ inch $$= 2.54 cm. $$Which of the following is correct?

Accepted Answer

$$2.54 cm$

Question 4

A prescription medication requires $$7.85 mg $$per kg of body weight. If a patient weighs $$70.0 kg$$, how many milligrams of medication should be administered?

Accepted Answer

$$549.5 mg$

Question 5

Which of the following correctly expresses $$0.0000874 in $$scientific notation?

Accepted Answer

$$8.74 	imes 10$$^{-5}$$

Question 6

A sample of an unknown metal has a mass of $$35.4 g $$and a volume of $$3.11 cm$^3. $$What is the density of the metal?

Accepted Answer

$$11.4 g/cm$^3$$

Question 7

Which of the following measurements contains exactly three significant figures?

Accepted Answer

$$0.0300 g$$

Question 8

A runner wants to run $$10.0 km. $$She knows her running pace is $$7.5$$ min/km. How many minutes must she run?

Accepted Answer

$$75$$ min$

Question 9

Which of the following is the correct result for $$6.02 	imes 10$$^{23}$$ \div 3.00 	imes 10$$^{8}$$, rounded to the correct number of significant figures?

Accepted Answer

$$2.01 	imes 10$$^{15}$$

Question 10

A beaker contains $$2.0$$ gal of gasoline. What is this quantity in cubic centimeters? ($$1$$ gal $$= 3.785 L$$, $$1 L$$ $$= 1000 cm$^3)$$

Accepted Answer

$$7.57 	imes 10$$^{3}$$ cm^3$

Question 11

Which of the following best describes the rule for determining the number of significant figures in the result of a multiplication or division calculation?

Accepted Answer

The result should have the same number of significant figures as the measurement with the fewest significant figures.

Question 12

A hydrogen atom has a volume of approximately $$6.2 	imes 10$$^{-31}$$ m^3$. Which of the following is the correct way to express this in cubic centimeters?

Accepted Answer

$$6.2 	imes 10$$^{-25}$$ cm^3$

Question 13

Which of the following is the correct conversion for $$1.0 km to $$nanometers?

Accepted Answer

$$1.0 	imes 10$$^{12}$$ nm$

Question 14

A student measures the length of a metal rod as $$12.30 cm. $$Which of the following statements is true regarding the significant figures in this measurement?

Accepted Answer

All digits, including the zero, are significant.

Question 15

Which of the following is the correct result for $$4.56 	imes 10$$^{3}$$ + 7.89 	imes 10$$^{2}$$, rounded to the correct number of significant figures?

Accepted Answer

$$5.35 	imes 10$$^{3}$$

Question 16

A prescription medication requires $$0.025 g $$per kg of body weight. If a patient weighs $$80.0 kg$$, how many grams of medication should be administered?

Accepted Answer

$$2.0 g$

Question 17

Which of the following is the correct way to convert $$5.08 	imes 10$$^{2}$$ miles to kilometers, given that 1$ mile = 1.61$ km?

Accepted Answer

$$5.08 	imes 10$$^{2}$$ 	imes 1.61 = 8.18 	imes 10$$^{2}$$ km$

Question 18

Which of the following best describes the meniscus and how it should be read in laboratory glassware?

Accepted Answer

The meniscus is the curved surface of a liquid and should be read at the lowest point of the curve at eye level.

Question 19

A cyclist rides at an average speed of $$24.2 mi/h. If he $$wants to bike $$195 km$$, how long (in hours) must he ride? ($$1 mi$$ $$= 1.61 km)$$

Accepted Answer

$$5.0 h$

Fundamental Measurements, Scientific Notation, and Significant Figures in Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard