Question 1

Which of the following statements best describes the difference between a physical and a chemical change?

Accepted Answer

A chemical change results in the formation of new substances, while a physical change does not.

Question 2

Which of the following is the correct formula for ammonium sulfate?

Accepted Answer

$$\mathrm{(NH_4$)_2SO_4}$$

Question 3

A sample of a compound contains 40.0\% carbon, 6.7\% hydrogen, and 53.3\% oxygen by mass. What is the empirical formula of this compound?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 4

Which of the following ions is polyatomic and carries a $$2-$$ charge?

Accepted Answer

$$\mathrm{SO_4$^{2-}} ($$sulfate)

Question 5

A student needs to convert $$250$$ milliliters to liters. Which of the following is the correct conversion factor and answer?

Accepted Answer

$$1\ \mathrm{mL} = 10$$^{-3}$$\ \mathrm{L}$$;\ 250\ \mathrm{mL} = 0.250\ \mathrm{L}$

Question 6

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

Accepted Answer

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

Question 7

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

Accepted Answer

Iron(III) oxide

Question 8

A reaction has a theoretical yield of $$10.0\ \mathrm{g}$$ and an actual yield of $$7.5\ \mathrm{g}. $$What is the percent yield?

Accepted Answer

$$75\%$$

Question 9

Which of the following is a chemical property?

Accepted Answer

Flammability

Question 10

What is the molar mass of $$\mathrm{Ca(NO_3$)_2}$$?

Accepted Answer

$$164\ \mathrm{g/mol}$$

Question 11

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 12

How many molecules are in $$0.50$$ moles of water ($$\mathrm{H_2O}$$)? (Avogadro's number $$= 6.022 	imes 10$$^{23}$$)

Accepted Answer

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

Question 13

Which of the following is the correct formula for the polyatomic ion chromate?

Accepted Answer

$$\mathrm{$$CrO_4$$^{2-}}$$

Question 14

A sample of silver has two naturally occurring isotopes: $$^{107}\mathrm{Ag} (51.8$$\%, mass = 106.905 amu) and $$^{109}\mathrm{Ag} (48.2$$\%, mass = 108.905 amu). What is the average atomic mass of silver?

Accepted Answer

$$107.9$$ amu

Question 15

Which of the following is a correct conversion from $$25\ ^\circ\mathrm{C} to $$Kelvin?

Accepted Answer

$$298\ \mathrm{K}$$

Question 16

Which of the following compounds is an ionic compound?

Accepted Answer

$$\mathrm{Na_2SO_4}$$

Question 17

What is the correct name for $$\mathrm{$$HNO_3$$}$$?

Accepted Answer

Nitric acid

Question 18

A $$5.00\ \mathrm{g}$$ sample of $$\mathrm{NaCl}$$ contains how many moles? (Molar mass of $$\mathrm{NaCl} = 58.44\ \mathrm{g/mol})$$

Accepted Answer

$$0.0856$$ moles

Question 19

Which of the following is the correct formula for the polyatomic ion acetate?

Accepted Answer

$$\mathrm{CH_3COO^-}$$

General Chemistry Exam 1 Study Guide: Matter, Measurement, Atoms, Molecules, and Reaction Stoichiometry

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