Q: How many oxygen atoms are contained in 47.6 g of Al$$_2(CO$_3$$)$$_3$$? (Molar mass Al$$_2(CO$_3$$)$$_3 = 233.99 g/$$mol)

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

Question 1

A sample of silver contains two naturally occurring isotopes: Ag-107 (106.90509 amu, 51.84%) and Ag-109 (108.90476 amu, 48.16%). What is the average atomic mass of silver?

Accepted Answer

$$108.19\ 	ext{amu}$$

Question 2

Which of the following statements about atomic structure is true?

Accepted Answer

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

Question 3

A metal weighs 45.42 g. When the metal is 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 4

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

Accepted Answer

KCN

Question 5

Combustion analysis of a hydrocarbon in gasoline yields 2.20 g CO$$_2$$ and 1.08 g H$$_2O. $$What is the empirical formula of the hydrocarbon?

Accepted Answer

$$\mathrm{CH}_2$$

Question 6

Which of the following is a heterogeneous mixture that can scatter light as a colloid?

Accepted Answer

Milk

Question 7

What is the percent composition of lithium in Li$$_3PO$_4$$? (Molar mass Li$$_3PO$_4 = 115.79 g/$$mol)

Accepted Answer

$$17.98\%$$

Question 8

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

Accepted Answer

Calcium

Question 9

A student measures the mass of a sample as 3.4010 g. How many significant figures does this number have?

Accepted Answer

5

Question 10

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

Accepted Answer

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

Question 11

What is the empirical formula for glucose, C$$_6H$_{12}O$_6$$?

Accepted Answer

$$\mathrm{CH}_2\mathrm{O}$$

Question 12

Which of the following statements is true regarding the law of conservation of mass?

Accepted Answer

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

Question 13

A solution contains 0.500 mol of NaCl in 250.0 mL of water. What is the molarity of the solution?

Accepted Answer

$$2.00\ 	ext{M}$$

Question 14

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 15

What is the molecular formula of a compound that has an empirical formula of CH$$_2$$ and a molar mass of 72.18 g/mol?

Accepted Answer

$$C_6H_{12}$$

Question 16

Which of the following is a physical change?

Accepted Answer

Condensation of water vapor to liquid water

Question 17

How many oxygen atoms are contained in 47.6 g of Al$$_2(CO$_3$$)$$_3$$? (Molar mass Al$$_2(CO$_3$$)$$_3 = 233.99 g/$$mol)

Accepted Answer

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

Question 18

Which of the following is the highest temperature?

Accepted Answer

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

Question 19

Which of the following is a correct statement about the periodic table?

Accepted Answer

Elements in the same group have similar chemical properties.

General Chemistry Exam Study Guide: Key Concepts, Equations, and Problem-Solving Strategies

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