Q: A sample contains 47.6 g of Al$$_2(CO$_3$$)$$_3. $$How many oxygen atoms are present in this sample? (Molar mass Al$$_2(CO$_3$$)$$_3 = 233.99 g/$$mol)

$$1.10 \times 10$$^{24}$$ atoms

Q: Which of the following pairs are isotopes of the same element?

$$^{12}\text{C}$$ and $$^{13}\text{C}$$

Q: Which of the following is the correct formula for calculating the average atomic mass?

$$\text{atomic mass} = \sum (\text{fractional abundance} \times \text{mass})_{\text{isotope}}$$

Question 1

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 2

A sample contains 47.6 g of Al$$_2(CO$_3$$)$$_3. $$How many oxygen atoms are present in this sample? (Molar mass Al$$_2(CO$_3$$)$$_3 = 233.99 g/$$mol)

Accepted Answer

$$1.10 	imes 10$$^{24}$$ atoms

Question 3

Which of the following is the correct empirical formula for glucose, C$$_6H$_{12}O$_6$$?

Accepted Answer

CH$$_2O$$

Question 4

Which of the following is NOT a physical change?

Accepted Answer

Burning gasoline in a car engine

Question 5

A metal weighs 45.42 g. When placed in a graduated cylinder containing water, the liquid level rises from 26.30 mL to 31.38 mL. What is the density of the metal?

Accepted Answer

$$8.84 	ext{ g/cm}^3$$

Question 6

Which of the following pairs are isotopes of the same element?

Accepted Answer

$$^{12}	ext{C}$$ and $$^{13}	ext{C}$$

Question 7

Which of the following statements about atomic structure is true?

Accepted Answer

A neutral atom contains the same number of protons and electrons.

Question 8

Which of the following compounds contains both ionic and covalent bonds?

Accepted Answer

NaNO$$_3$$

Question 9

A student measures the mass of a sample as 8.39 x 10$$^{-1} g $$and its volume as 4.0118 mL. What is the density of the sample?

Accepted Answer

$$0.209 	ext{ g/mL}$$

Question 10

Which of the following is a heterogeneous mixture?

Accepted Answer

A bowl of salad

Question 11

Which of the following is the correct balanced equation for the reaction of aqueous aluminum acetate with aqueous ammonium phosphate to form solid aluminum phosphate and aqueous ammonium acetate?

Accepted Answer

$$Al(C_2H_3O_2)_3(aq) + (NH_4$)_3PO_4(aq) \rightarrow $$AlPO_4$$(s) + 3 NH_4C_2H_3O_2(aq)$$

Question 12

Which of the following elements will most likely form ionic bonds in compounds?

Accepted Answer

Calcium

Question 13

What is the molar mass of Ca$$_3(PO$_4$$)$$_2$$?

Accepted Answer

$$310.17 	ext{ g/mol}$$

Question 14

Which of the following is the highest temperature?

Accepted Answer

$$274^\circ 	ext{C}$$

Question 15

Which of the following is a chemical property?

Accepted Answer

Iron rusts when exposed to oxygen.

Question 16

A compound contains 10.15 g P and 34.85 g Cl. What is the empirical formula?

Accepted Answer

PCl$$_3$$

Question 17

Which of the following is a molecular element?

Accepted Answer

O$$_2$$

Question 18

Which of the following is the correct statement about the Law of Multiple Proportions?

Accepted Answer

When two elements form more than one compound, the masses of one element that combine with a fixed mass of the other are in ratios of small whole numbers.

Question 19

Which of the following is the correct formula for calculating the average atomic mass?

Accepted Answer

$$	ext{atomic mass} = \sum (	ext{fractional abundance} 	imes 	ext{mass})_{	ext{isotope}}$$

General Chemistry I: Study Guide for Exam 1 (Chapters 1–4)

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