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 4.56 g, 4.57 g, and 4.55 g in three trials. 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 scientific notation for the number 0.000345?

Accepted Answer

$$3.45 	imes 10$$^{-4}$$

Question 4

How many significant figures are in the measurement 0.02030 L?

Accepted Answer

4

Question 5

Which of the following correctly matches the group number with its family name on the periodic table?

Accepted Answer

Group 1A: Alkali Metals

Question 6

An atom has 17 protons, 18 neutrons, and 17 electrons. What is its atomic number and mass number?

Accepted Answer

Atomic number = 17, Mass number = 35

Question 7

Which of the following is the correct formula for magnesium chloride?

Accepted Answer

$$\mathrm{$$MgCl_2$$}$$

Question 8

What is the name of the compound $$\mathrm{Fe_2O_3}$$?

Accepted Answer

Iron(III) oxide

Question 9

Which of the following is a correct Lewis structure for carbon dioxide ($$\mathrm{CO_2$}$$)?

Accepted Answer

O=C=O, with each O atom having two lone pairs

Question 10

Which of the following best describes a combustion reaction?

Accepted Answer

A hydrocarbon reacts with oxygen to produce carbon dioxide and water.

Question 11

How many moles are in 18.0 g of water ($$\mathrm{H_2O}$$)? (Molar mass of $$\mathrm{H_2O} = 18.0 g/$$mol)

Accepted Answer

1.00 mol

Question 12

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

Accepted Answer

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

Question 13

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of $$\mathrm{$$CO_2$$}$$. How many moles of $$\mathrm{$$CO_2$$}$$ are present?

Accepted Answer

0.500 mol

Question 14

Which of the following statements about ionic and covalent compounds is correct?

Accepted Answer

Ionic compounds are formed from metals and nonmetals, while covalent compounds are formed from nonmetals only.

Question 15

What is the percent composition by mass of oxygen in water ($$\mathrm{H_2O}$$)? (Atomic masses: H = 1.0, O = 16.0)

Accepted Answer

89%

Question 16

Which of the following is the correct name for $$\mathrm{N_2O_5}$$?

Accepted Answer

Dinitrogen pentoxide

Question 17

A reaction has the following balanced equation: $$2\mathrm{Al} + 3\mathrm{Cl_2$} \rightarrow 2\mathrm{$$AlCl_3$$}. If $$you start with 4.0 mol of Al and excess $$\mathrm{Cl_2$}$$, how many moles of $$\mathrm{$$AlCl_3$$}$$ can be formed?

Accepted Answer

4.0 mol

Question 18

Which of the following is a correct example of a single displacement reaction?

Accepted Answer

$$\mathrm{Zn + 2HCl \rightarrow $$ZnCl_2$$ + H_2$}$$

Question 19

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

Accepted Answer

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

Exam 1 Review: Measurements, Atoms & Elements, Compounds, and Chemical Reactions

Guida di studio - Domande di pratica

Study guide - Flashcard