Q: A laboratory sample has a mass of $$0.451\ \mathrm{kg}. $$Convert this mass to milligrams ($$\mathrm{mg}) $$using the appropriate metric prefixes.

$$4.51 \times 10^5$\ \mathrm{mg}$$

Question 1

Which of the following is the correct SI base unit and abbreviation for measuring the amount of substance?

Accepted Answer

Mole (mol)

Question 2

A laboratory sample has a mass of $$0.451\ \mathrm{kg}. $$Convert this mass to milligrams ($$\mathrm{mg}) $$using the appropriate metric prefixes.

Accepted Answer

$$4.51 	imes 10^5$\ \mathrm{mg}$$

Question 3

Which of the following best describes the difference between accuracy and precision in scientific measurements?

Accepted Answer

Accuracy is how close a measurement is to the true value, while precision is how close repeated measurements are to each other.

Question 4

A cube of gold has a length of $$2.00\ \mathrm{cm} on $$each side. Given the density of gold is $$19.32\ \mathrm{g/cm^3$}$$, what is the mass of the cube?

Accepted Answer

$$154.6\ \mathrm{g}$$

Question 5

Which of the following is a derived SI unit?

Accepted Answer

Meter per second ($$\mathrm{m/s})$$

Question 6

A graduated cylinder contains a liquid with a meniscus at $$4.3\ \mathrm{mL}. $$What is the correct way to report this measurement, considering significant figures?

Accepted Answer

$$4.30\ \mathrm{mL}$$

Question 7

Which of the following statements about mixtures and pure substances is correct?

Accepted Answer

A homogeneous mixture has uniform composition throughout, while a heterogeneous mixture does not.

Question 8

Which laboratory equipment would you use to deliver a specific, fixed volume of liquid most accurately?

Accepted Answer

Pipette

Question 9

A sample of ethanol has a mass of $$15.8\ \mathrm{g}$$ and a volume of $$20.0\ \mathrm{mL}. $$What is the density of ethanol in $$\mathrm{g/mL}$$, reported to the correct number of significant figures?

Accepted Answer

$$0.790\ \mathrm{g/mL}$$

Question 10

Which of the following is an example of a physical change?

Accepted Answer

Ice melting into liquid water

Question 11

A solution is prepared by dissolving table salt in water. Which method would best separate the salt from the water?

Accepted Answer

Distillation

Question 12

Which of the following best describes the law of definite proportions?

Accepted Answer

A given compound always contains the same proportion of elements by mass.

Question 13

Which experiment led to the discovery of the nucleus in the atom?

Accepted Answer

Rutherford's gold foil experiment

Question 14

A chlorine isotope has 17 protons and 18 neutrons. What is its atomic number, mass number, and symbol?

Accepted Answer

Atomic number: 17, Mass number: 35, Symbol: $$^{35}\mathrm{Cl}$$

Question 15

Which of the following statements about ions is correct?

Accepted Answer

An anion is formed when an atom gains electrons.

Question 16

Calculate the atomic mass of chlorine if it consists of $$75.77\%$$ $$^{35}\mathrm{Cl} ($$mass $$= 34.97\ \mathrm{amu}) $$and $$24.23\%$$ $$^{37}\mathrm{Cl} ($$mass $$= 36.97\ \mathrm{amu}).$$

Accepted Answer

$$35.45\ \mathrm{amu}$$

Question 17

Which of the following is the correct conversion for $$1\ \mathrm{L} to$$ $$\mathrm{cm^3$}$$?

Accepted Answer

$$1\ \mathrm{L} = 1000\ \mathrm{cm^3$}$$

Question 18

A student multiplies $$3.12\ \mathrm{cm} by$$ $$2.1\ \mathrm{cm} to $$find the area of a rectangle. What is the correct answer with the proper number of significant figures?

Accepted Answer

$$6.6\ \mathrm{cm^2$}$$

Question 19

Which of the following prefixes represents $$10^{-6}$$?

Accepted Answer

Micro ($$\mu)$$

Matter and Measurement: Foundations of General Chemistry

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