Question 1

Which of the following best describes the difference between a physical and a chemical change? Consider the following scenarios:

1. Ice melting in a glass
2. Iron rusting when exposed to air
3. Sugar dissolving in water
4. Paper burning in a fire

Which pair correctly matches a physical change and a chemical change?

Accepted Answer

1 is a physical change; 2 is a chemical change

Question 2

A student measures the mass of a sample three times and records the following values: 12.34 g, 12.3 g, and 12.345 g. What is the correct way to report the average mass with the appropriate number of significant figures?

Accepted Answer

Question 3

Which of the following statements about the periodic table is TRUE?

Accepted Answer

Elements in the same group have the same number of valence electrons.

Question 4

Which of the following is an example of a compound?

Accepted Answer

Sodium chloride ($$\mathrm{NaCl})$$

Question 5

What is the correct formula for magnesium chloride?

Accepted Answer

$$\mathrm{MgCl}_2$$

Question 6

A solution is prepared by dissolving $$5.00\ \mathrm{mol} of $$sodium chloride in enough water to make $$2.00\ \mathrm{L} of $$solution. What is the molarity of the solution?

Accepted Answer

$$2.50\ \mathrm{M}$$

Question 7

Which of the following best describes the law of conservation of mass?

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 8

Which of the following is a balanced chemical equation for the reaction of hydrogen gas with oxygen gas to form water?

Accepted Answer

$$2\mathrm{H}_2 + \mathrm{O}_2 \rightarrow 2\mathrm{H}_2\mathrm{O}$$

Question 9

How many grams of carbon dioxide ($$\mathrm{CO}_2) $$are produced when $$44.0\ \mathrm{g} of $$propane ($$\mathrm{C}_3\mathrm{H}_8) is $$burned in excess oxygen? (Molar mass of $$\mathrm{C}_3\mathrm{H}_8 = 44.0\ \mathrm{g/mol}$$, $$\mathrm{CO}_2 = 44.0\ \mathrm{g/mol}$$)

$$\mathrm{C}_3\mathrm{H}_8 + 5\mathrm{O}_2 \rightarrow 3\mathrm{CO}_2 + 4\mathrm{H}_2\mathrm{O}$$

Accepted Answer

$$132\ \mathrm{g}$$

Question 10

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the transfer of electrons from a metal to a nonmetal.

Question 11

Which of the following is the correct Lewis structure for methane ($$\mathrm{CH}_4$$)?

Accepted Answer

A central carbon atom with four single bonds to four hydrogen atoms.

Question 12

Which of the following elements is most likely to form a $$2+$$ ion?

Accepted Answer

Magnesium ($$\mathrm{Mg})$$

Question 13

A student mixes solutions of silver nitrate ($$\mathrm{AgNO}_3) $$and sodium chloride ($$\mathrm{NaCl}). A $$white precipitate forms. What is the identity of the precipitate?

Accepted Answer

$$\mathrm{AgCl}$$

Question 14

Which of the following best describes the trend in atomic radius across a period from left to right on the periodic table?

Accepted Answer

Atomic radius decreases.

Question 15

Which of the following is the correct name for $$\mathrm{Fe}_2\mathrm{O}_3$$?

Accepted Answer

Iron(III) oxide

Question 16

A $$25.0\ \mathrm{mL}$$ sample of $$0.200\ \mathrm{M}$$ hydrochloric acid ($$\mathrm{HCl}) is $$neutralized by $$0.100\ \mathrm{M}$$ sodium hydroxide ($$\mathrm{NaOH}). $$What volume of $$\mathrm{NaOH} is $$required?

$$\mathrm{HCl} + \mathrm{NaOH} \rightarrow \mathrm{NaCl} + \mathrm{H}_2\mathrm{O}$$

Accepted Answer

$$50.0\ \mathrm{mL}$$

Question 17

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 18

Which of the following is a single replacement reaction?

Accepted Answer

$$\mathrm{Zn} + 2\mathrm{HCl} \rightarrow \mathrm{ZnCl}_2 + \mathrm{H}_2$$

Question 19

Which of the following statements about covalent bonds is correct?

Accepted Answer

Covalent bonds involve the sharing of electrons between two nonmetals.

Question 20

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of glucose ($$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$$). How many moles of glucose are present?

Accepted Answer

$$0.500\ \mathrm{mol}$$

Chemistry I Syllabus and Course Overview – Massachusetts Maritime Academy

Guida di studio - Domande di pratica

Study guide - Flashcard