Question 1

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

Accepted Answer

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

Question 2

A student measures the mass of a sample as 4.50 g, 4.51 g, and 4.49 g. The true mass is 5.00 g. Which statement is correct about the student's measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 3

Which of the following is the correct number of significant figures in the measurement 0.0045600 L?

Accepted Answer

6

Question 4

Which of the following correctly expresses Avogadro's number?

Accepted Answer

$$6.02 	imes 10$$^{23}$$

Question 5

A neutral atom of chlorine has an atomic number of 17 and a mass number of 35. How many neutrons does it have?

Accepted Answer

18

Question 6

Which of the following elements is a noble gas?

Accepted Answer

Neon

Question 7

What is the correct formula for the compound formed between magnesium and nitrogen?

Accepted Answer

$$\mathrm{Mg_3N_2}$$

Question 8

Which of the following is the correct name for $$\mathrm{$$FeCl_3$$}$$?

Accepted Answer

Iron(III) chloride

Question 9

Which of the following is a molecular compound?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 10

What is the molar mass of $$\mathrm{Ca(OH)_2}$$? (Atomic masses: Ca = 40.1, O = 16.0, H = 1.0)

Accepted Answer

74.1 g/mol

Question 11

How many molecules are in 0.50 mol of $$\mathrm{H_2O}$$?

Accepted Answer

$$3.01 	imes 10$$^{23}$$

Question 12

Which of the following is the correct balanced equation for the combustion of methane ($$\mathrm{CH_4$}$$)?

Accepted Answer

$$\mathrm{CH_4$} + 2\mathrm{O_2$} \rightarrow \mathrm{CO_2$} + 2\mathrm{H_2O}$$

Question 13

Which of the following is a single displacement reaction?

Accepted Answer

$$\mathrm{Zn} + \mathrm{$$CuSO_4$$} \rightarrow \mathrm{$$ZnSO_4$$} + \mathrm{Cu}$$

Question 14

A sample contains 18.0 g of glucose ($$\mathrm{C_6H_{12}O_6$}$$, molar mass = 180 g/mol). How many moles of glucose are present?

Accepted Answer

0.10 mol

Question 15

Which of the following best describes the octet rule?

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve eight electrons in their valence shell.

Question 16

Which of the following acids is correctly named?

Accepted Answer

$$\mathrm{H_2SO_4}$$: sulfuric acid

Question 17

A solution contains 0.25 mol of $$\mathrm{NaCl}$$ dissolved in enough water to make 0.50 L of solution. What is the molarity of the solution?

Accepted Answer

0.50 M

Question 18

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 19

Which of the following best describes a limiting reagent in a chemical reaction?

Accepted Answer

The reactant that is completely consumed first, limiting the amount of product formed.

GOB Chemistry Exam 1 Review: Measurements, Atoms, Compounds, and Reactions

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