Q: A sample of water has a mass of $$36.0 g $$and a volume of $$36.0 mL. $$What is the density, and how many significant figures should the answer have?

$$1.00\ \text{g/mL}$$ with 3 significant figures

Q: A student needs to convert $$0.250 L to mL. $$Which calculation is correct?

$$0.250\ \text{L} \times \dfrac{1000\ \text{mL}}{1\ \text{L}}$$

Question 1

A student measures the mass of a sample four times and obtains the following values: 5.12 g, 5.13 g, 5.11 g, and 5.12 g. The true mass is 5.50 g. Which statement best describes the accuracy and precision of these measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 2

Which of the following is an example of an intensive property?

Accepted Answer

Density

Question 3

How many significant figures are in the measurement 0.0045200 kg?

Accepted Answer

$$6$$

Question 4

A chemist needs to convert $$2.50$$ inches to centimeters using the conversion factor $$1\ 	ext{in} = 2.54\ 	ext{cm}. $$What is the correct answer with the proper number of significant figures?

Accepted Answer

$$6.35\ 	ext{cm}$$

Question 5

Which of the following best describes a homogeneous mixture?

Accepted Answer

Air in a classroom

Question 6

Which SI unit is correctly matched with its physical quantity?

Accepted Answer

Mass — $$	ext{kg}$$

Question 7

Which laboratory technique would be most appropriate to separate a mixture of sand and salt water?

Accepted Answer

Filtration

Question 8

A student records the length of a metal rod as $$12.30 cm. $$Which digit is the estimated digit, and what does it represent?

Accepted Answer

The '0' is the estimated digit; it represents the uncertainty in the hundredths place.

Question 9

Which of the following is an example of applied science?

Accepted Answer

Developing a new drug to treat cancer

Question 10

Which area of chemistry focuses on the study of compounds containing carbon?

Accepted Answer

Organic chemistry

Question 11

A sample of water has a mass of $$36.0 g $$and a volume of $$36.0 mL. $$What is the density, and how many significant figures should the answer have?

Accepted Answer

$$1.00\ 	ext{g/mL}$$ with 3 significant figures

Question 12

Which of the following is a derived SI unit?

Accepted Answer

$$	ext{m}^3$$

Question 13

Which property would change if you cut a block of copper in half?

Accepted Answer

Mass

Question 14

A student needs to convert $$0.250 L to mL. $$Which calculation is correct?

Accepted Answer

$$0.250\ 	ext{L} 	imes \dfrac{1000\ 	ext{mL}}{1\ 	ext{L}}$$

Question 15

Which technique would best separate a solution of salt dissolved in water to recover the salt?

Accepted Answer

Evaporation

Question 16

Which of the following statements about significant figures is correct?

Accepted Answer

Exact counted values have infinite significant figures.

Question 17

A mixture of oil and water is best described as:

Accepted Answer

A heterogeneous mixture

Question 18

Which of the following is NOT one of the five main areas of chemistry?

Accepted Answer

Nuclear chemistry

Question 19

A scientist measures the boiling point of a liquid three times and gets $$78.1\ ^\circ	ext{C}$$, $$78.3\ ^\circ	ext{C}$$, and $$78.2\ ^\circ	ext{C}. $$The accepted value is $$82.0\ ^\circ	ext{C}. $$What can be said about the measurements?

Accepted Answer

They are precise but not accurate.

Question 20

Which separation technique would be most effective for separating two liquids with different boiling points, such as ethanol and water?

Accepted Answer

Distillation

Measurement, Units, Properties of Matter, and Separation Techniques in General Chemistry

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