Q: A chemist needs $$0.250 kg of a $$compound. How many grams is this, and what is the correct number of significant figures?

$$2.50 \times 10$$^{2}$$ \text{ g}$

Question 1

Which of the following numbers is correctly written in scientific notation?

Accepted Answer

$$4.5 	imes 10$$^{1}$$

Question 2

Convert $$3.2 	imes 10$$^{4}$$ to standard notation.

Accepted Answer

$$32,000$$

Question 3

How many significant figures are in the number $$0.004560$$?

Accepted Answer

$$5$$

Question 4

Round $$0.007892 to $$three significant figures.

Accepted Answer

$$0.00789$$

Question 5

What is the result of $$12.11 + 0.034 + 1.3$$ rounded to the correct number of significant figures?

Accepted Answer

$$13.4$$

Question 6

Which of the following is the correct rule for determining the number of significant figures in a multiplication calculation?

Accepted Answer

The answer should have as many significant figures as the number with the fewest significant figures.

Question 7

A student measures the mass of a sample as $$12.3 g $$and its volume as $$4.56 mL. $$What is the density, rounded to the correct number of significant figures?

Accepted Answer

$$2.7$$ 	ext{ g/mL}$

Question 8

Which of the following is the correct SI unit for temperature?

Accepted Answer

Kelvin

Question 9

What is the value of the metric prefix 'milli-'?

Accepted Answer

$$10^{-3}$$

Question 10

Convert $$2500 mg to $$grams and round to the correct number of significant figures.

Accepted Answer

$$2.50$$ 	ext{ g}$

Question 11

A patient is prescribed $$2.50$$ grams of medication. The pharmacy only has $$500 mg $$tablets. How many tablets should the patient take? (Round to the correct number of significant figures.)

Accepted Answer

$$5.0$$

Question 12

Which of the following is the correct definition of density?

Accepted Answer

The ratio of mass to volume.

Question 13

Convert $$3.00$$ miles to kilometers. ($$1$$ mile $$= 1.609 km) $$Round to the correct number of significant figures.

Accepted Answer

$$4.83$$ 	ext{ km}$

Question 14

A sample has a density of $$1.25 g/mL $$and a mass of $$10.0 g. $$What is its volume, rounded to the correct number of significant figures?

Accepted Answer

$$8.0$$ 	ext{ mL}$

Question 15

Which of the following is the correct SI unit for mass?

Accepted Answer

Kilogram

Question 16

A laboratory solution is prepared by mixing $$12.0 mL of $$water with $$0.00560 L of $$ethanol. What is the total volume in mL, rounded to the correct number of significant figures?

Accepted Answer

$$17.6$$ 	ext{ mL}$

Question 17

Which calculation correctly applies the rules for significant figures: $$2.34 	imes 1.2$$?

Accepted Answer

$$2.8$$

Question 18

A block of metal has a mass of $$75.0 g $$and a volume of $$15.0 mL. $$What is its density, rounded to the correct number of significant figures?

Accepted Answer

$$5.0$$ 	ext{ g/mL}$

Question 19

Which metric prefix represents $$10^{-9}$$?

Accepted Answer

Nano-

Question 20

A chemist needs $$0.250 kg of a $$compound. How many grams is this, and what is the correct number of significant figures?

Accepted Answer

$$2.50 	imes 10$$^{2}$$ 	ext{ g}$

Chapter 2 Study Guide: Scientific Notation, Significant Figures, SI Units, and Density

Guida di studio - Domande di pratica

Study guide - Flashcard