Q: How many atoms are present in a $$10.0\ \mathrm{g}$$ sample of aluminum ($$\mathrm{Al}$$, molar mass $$26.98\ \mathrm{g/mol}$$)?

$$2.23 \times 10$$^{23}$$ atoms

Question 1

A student measures the mass of a metal sample as 12.34 g and its volume as 4.5 mL. What is the density of the metal, reported to the correct number of significant figures?

Accepted Answer

$$2.7\ \mathrm{g/mL}$$

Question 2

Which of the following is a homogeneous mixture?

Accepted Answer

Salt water

Question 3

An atom has 17 protons, 18 neutrons, and 18 electrons. Which isotope is it, and what is its charge?

Accepted Answer

Chlorine-35, $$1^-$$ charge

Question 4

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

Accepted Answer

Iron(III) chloride

Question 5

Which statement is NOT part of Rutherford's nuclear model of the atom?

Accepted Answer

Electrons are embedded within a positively charged sphere.

Question 6

Convert a temperature of $$25\ ^\circ\mathrm{C} to $$Kelvin.

Accepted Answer

$$298\ \mathrm{K}$$

Question 7

Given the formula $$\mathrm{C_2H_6}$$, what types of bonds exist between the carbon atoms?

Accepted Answer

Single covalent bond

Question 8

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 9

Which of the following is a physical change?

Accepted Answer

Melting of ice

Question 10

Which of the following equations correctly represents the balanced combustion of propane ($$\mathrm{C_3H_8}) in $$oxygen?

Accepted Answer

$$\mathrm{C_3H_8} + 5\mathrm{O_2$} \rightarrow 3\mathrm{CO_2$} + 4\mathrm{H_2O}$$

Question 11

A neutral atom has an atomic number of 12 and a mass number of 24. How many protons, neutrons, and electrons does it have?

Accepted Answer

12 protons, 12 neutrons, 12 electrons

Question 12

Which of the following volumes is the smallest?

Accepted Answer

$$0.3\ \mathrm{L}$$

Question 13

Which of the following is a chemical change?

Accepted Answer

Burning wood

Question 14

Which statement is FALSE regarding noble gases?

Accepted Answer

They are highly reactive.

Question 15

How many atoms are present in a $$10.0\ \mathrm{g}$$ sample of aluminum ($$\mathrm{Al}$$, molar mass $$26.98\ \mathrm{g/mol}$$)?

Accepted Answer

$$2.23 	imes 10$$^{23}$$ atoms

Question 16

Which type of bond is most likely to form between sodium and chlorine?

Accepted Answer

Ionic bond

Question 17

Given two isotopes of magnesium: $$^{24}\mathrm{Mg} (78.99$$%, 23.985 amu) and $$^{26}\mathrm{Mg} (11.01$$%, 25.983 amu), what is the average atomic mass?

Accepted Answer

$$24.31\ \mathrm{amu}$$

Question 18

Which of the following compound names and formulas is INCORRECT?

Accepted Answer

Magnesium sulfide: $$\mathrm{$$MgSO_4$$}$$

Question 19

Calculate the molar mass of $$\mathrm{C_6H_{12}O_6$} ($$glucose).

Accepted Answer

$$180.16\ \mathrm{g/mol}$$

Question 20

Which of the following is NOT a property of metals?

Accepted Answer

Brittle

General Chemistry Exam I Study Guide: Key Concepts and Skills

Guida di studio - Domande di pratica

Study guide - Flashcard