Chapter 3

What charges are most commonly observed for monatomic ions of the following elements? (a) magnesium (c) nickel (b) zinc (d) gallium

What charges are most commonly observed for monatomic ions of the following elements? (a) selenium (c) iron (b) fluorine (d) nitrogen

Give the symbol, including the correct charge, for each of the following ions: (a) barium ion (b) titanium(IV) ion (c) phosphate ion (d) hydrogen carbonate ion (e) sulfide ion (f) perchlorate ion (g) cobalt(II) ion (h) sulfate ion

Give the symbol, including the correct charge, for each of the following ions: (a) permanganate ion (b) nitrite ion (c) dihydrogen phosphate ion (d) ammonium ion (e) phosphate ion (f) sulfite ion

When a potassium atom becomes a monatomic ion, how many electrons does it lose or gain? What noble gas atom has the same number of electrons as a potassium ion?

When oxygen and sulfur atoms become monatomic ions, how many electrons does each lose or gain? Which noble gas atom has the same number of electrons as an oxygen ion? Which noble gas atom has the same number of electrons as a sulfur ion?

Predict the charges of the ions in an ionic compound containing the elements barium and bromine. Write the formula for the compound.

What are the charges of the ions in an ionic compound containing cobalt(III) and fluoride ions? Write the formula for the compound.

For each of the following compounds, give the formula, charge, and the number of each ion that makes up the compound: (a) \(\mathrm{K}_{2} \mathrm{S}\) (b) \(\cos \mathrm{O}_{4}\) (c) \(\mathrm{KMnO}_{4}\) (d) \(\left(\mathrm{NH}_{4}\right)_{3} \mathrm{PO}_{4}\) (e) \(\mathrm{Ca}(\mathrm{ClO})_{2}\)

For each of the following compounds, give the formula, charge, and the number of each ion that makes up the compound: (a) \(\mathrm{Mg}\left(\mathrm{CH}_{3} \mathrm{CO}_{2}\right)_{2}\) (d) \(\operatorname{Ti}\left(\mathrm{SO}_{4}\right)_{2}\) (b) \(\mathrm{Al}(\mathrm{OH})_{3}\) (c) \(\mathrm{KH}_{2} \mathrm{PO}_{4}\) (e) \(\mathrm{CuCO}_{3}\)

Cobalt forms \(\mathrm{Co}^{2+}\) and \(\mathrm{Co}^{3+}\) ions. Write the formulas for the two cobalt oxides formed by these transition metal ions.

Platinum is a transition element and forms \(\mathrm{Pt}^{2+}\) and \(\mathrm{Pt}^{4+}\) ions. Write the formulas for the compounds of each of these ions with (a) chloride ions and (b) sulfide ions.

Which of the following are correct formulas for ionic compounds? For those that are not, give the correct formula. (a) \(\mathrm{AlCl}_{2}\) (c) \(\mathrm{Ga}_{2} \mathrm{O}_{3}\) (b) \(\mathrm{KF}_{2}\) (d) MgS

Which of the following are correct formulas for ionic compounds? For those that are not, give the correct formula. (a) \(\mathrm{Ca}_{2} \mathrm{O}\) (c) \(\mathrm{Fe}_{2} \mathrm{O}_{5}\) (b) \(\mathrm{SrBr}_{2}\) (d) \(\mathrm{Li}_{2} \mathrm{O}\)

Name each of the following ionic compounds: (a) \(\mathrm{K}_{2} \mathrm{S}\) (c) \(\left(\mathrm{NH}_{4}\right)_{3} \mathrm{PO}_{4}\) (b) \(\cos 0_{4}\) (d) \(\mathrm{Ca}(\mathrm{ClO})_{2}\)

Name each of the following ionic compounds: (a) \(\mathrm{Ca}\left(\mathrm{CH}_{3} \mathrm{CO}_{2}\right)_{2}\) (c) \(\mathrm{Al}(\mathrm{OH})_{3}\) (b) \(\mathrm{Ni}_{3}\left(\mathrm{PO}_{4}\right)_{2}\) (d) \(\mathrm{KH}_{2} \mathrm{PO}_{4}\)

Give the formula for each of the following ionic compounds: (a) ammonium carbonate (b) calcium iodide (c) copper(II) bromide (d) aluminum phosphate (e) silver(I) acetate

Give the formula for each of the following ionic compounds: (a) calcium hydrogen carbonate (b) potassium permanganate (c) magnesium perchlorate (d) potassium hydrogen phosphate (e) sodium sulfite

Write the formulas for the four ionic compounds that can be made by combining each of the cations \(\mathrm{Na}^{+}\) and \(\mathrm{Ba}^{2+}\) with the anions \(\mathrm{CO}_{3}^{2-}\) and \(\mathrm{I}^{-}\). Name each of the compounds.

Write the formulas for the four ionic compounds that can be made by combining the cations \(\mathrm{Mg}^{2+}\) and \(\mathrm{Fe}^{3+}\) with the anions \(\mathrm{PO}_{4}^{3-}\) and \(\mathrm{NO}_{3}^{-} .\) Name each compound formed.

Sodium ion, Na \(^{+}\), forms ionic compounds with fluoride, \(\mathrm{F}^{-},\) and iodide, \(\mathrm{I}^{-} .\) The radii of these ions are as follows: \(\mathrm{Na}^{+}=116 \mathrm{pm} ; \mathrm{F}^{-}=119 \mathrm{pm} ;\) and \(\mathrm{I}^{-}=206 \mathrm{pm} .\) In which ionic compound, NaF or NaI, are the forces of attraction between cation and anion stronger? Explain your answer.

Consider the two ionic compounds NaCl and CaO. In which compound are the cation-anion attractive forces stronger? Explain your answer.

Name each of the following binary, nonionic compounds: (a) \(\mathrm{NF}_{3}\) (b) HI (c) \(\mathrm{BI}_{3}\) (d) \(\mathrm{PF}_{5}\)

Name each of the following binary, nonionic compounds: (a) \(\mathrm{N}_{2} \mathrm{O}_{5}\) (b) \(\mathrm{P}_{4} \mathrm{S}_{3}\) (c) \(\mathrm{OF}_{2}\) (d) \(\mathrm{XeF}_{4}\)

Give the formula for each of the following compounds: (a) sulfur dichloride (b) dinitrogen pentaoxide (c) silicon tetrachloride (d) diboron trioxide (commonly called boric oxide)

Give the formula for each of the following compounds: (a) bromine trifluoride (b) xenon difluoride (c) hydrazine (d) diphosphorus tetrafluoride (e) butane

Calculate the molar mass of each of the following compounds: (a) \(\mathrm{Fe}_{2} \mathrm{O}_{3},\) iron (III) oxide (b) \(\mathrm{BCl}_{3},\) boron trichloride (c) \(\left.\mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{6}, \text { ascorbic acid (vitamin } \mathrm{C}\right)\)

Calculate the molar mass of each of the following compounds: (a) \(\mathrm{Fe}\left(\mathrm{C}_{6} \mathrm{H}_{11} \mathrm{O}_{7}\right)_{2},\) iron \((\mathrm{II})\) gluconate, a dietary supplement (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{SH},\) butanethiol, has a skunk-like odor (c) \(\mathrm{C}_{20} \mathrm{H}_{24} \mathrm{N}_{2} \mathrm{O}_{2},\) quinine, used as an antimalarial drug

Calculate the molar mass of each hydrated compound. Note that the water of hydration is included in the molar mass. (See Section 3.7 .) (a) \(\mathrm{Ni}\left(\mathrm{NO}_{3}\right)_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}\)

Calculate the molar mass of each hydrated compound. Note that the water of hydration is included in the molar mass. (See Section 3.7.) (a) \(\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4} \cdot 2 \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{MgSO}_{4} \cdot 7 \mathrm{H}_{2} \mathrm{O},\) Epsom salts

What mass is represented by 0.0255 mol of each of the following compounds? (a) \(\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{OH},\) propanol, rubbing alcohol (b) \(\mathrm{C}_{11} \mathrm{H}_{16} \mathrm{O}_{2},\) an antioxidant in foods, also known as BHA (butylated hydroxyanisole) (c) \(\mathrm{C}_{9} \mathrm{H}_{8} \mathrm{O}_{4},\) aspirin

Assume you have 0.123 mol of each of the following compounds. What mass of each is present? (a) \(\mathrm{C}_{14} \mathrm{H}_{10} \mathrm{O}_{4},\) benzoyl peroxide, used in acne medications (c) \(\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{2},\) cisplatin, a cancer chemotherapy agent

Acetonitrile, \(\mathrm{CH}_{3} \mathrm{CN},\) was found in the tail of Comet HaleBopp in \(1997 .\) What amount (moles) of acetonitrile is represented by \(2.50 \mathrm{kg} ?\)

Acetone, \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CO},\) is an important industrial solvent. If 1260 million \(\mathrm{kg}\) of this organic compound is produced annually, what amount (moles) is produced?

Sulfur trioxide, \(\mathrm{SO}_{3},\) is made industrially in enormous quantities by combining oxygen and sulfur dioxide, \(\mathrm{SO}_{2}\) What amount (moles) of \(\mathrm{SO}_{3}\) is represented by \(1.00 \mathrm{kg}\) of sulfur trioxide? How many molecules? How many sulfur atoms? How many oxygen atoms?

An Alka-Seltzer tablet contains 324 mg of aspirin \(\left(\mathrm{C}_{9} \mathrm{H}_{8} \mathrm{O}_{4}\right), 1904 \mathrm{mg}\) of \(\mathrm{NaHCO}_{3},\) and \(1000 .\) mg of citric acid \(\left(\mathrm{H}_{3} \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{O}_{7}\right) .\) (The last two compounds react with each other to provide the "fizz," bubbles of \(\mathrm{CO}_{2},\) when the tablet is put into water.) (a) Calculate the amount (moles) of each substance in the tablet. (b) If you take one tablet, how many molecules of aspirin are you consuming?

Calculate the mass percent of each element in the following compounds. (a) PbS, lead(II) sulfide, galena (b) \(\mathrm{C}_{3} \mathrm{H}_{8},\) propane (c) \(\mathrm{C}_{10} \mathrm{H}_{14} \mathrm{O},\) carvone, found in caraway seed oil

Calculate the mass percent of each element in the following compounds: (a) \(\mathrm{C}_{8} \mathrm{H}_{10} \mathrm{N}_{2} \mathrm{O}_{2},\) caffeine (b) \(\mathrm{C}_{10} \mathrm{H}_{20} \mathrm{O},\) menthol (c) \(\mathrm{CoCl}_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}\)

Calculate the weight percent of iron in \(\mathrm{Fe}_{2} \mathrm{O}_{3},\) iron (III) oxide. What mass of iron (in grams) is present in \(25.0 \mathrm{g}\) of \(\mathrm{Fe}_{2} \mathrm{O}_{3} ?\)

Calculate the weight percent of copper in CuS, copper(II) sulfide. If you wish to obtain \(10.0 \mathrm{g}\) of copper metal from copper(II) sulfide, what mass of the sulfide (in grams) must you use?

Calculate the weight percent of titanium in the mineral ilmenite, FeTiO \(_{3}\). What mass of ilmenite (in grams) is required if you wish to obtain 750 g of titanium?

Succinic acid occurs in fungi and lichens. Its empirical formula is \(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\) and its molar mass is \(118.1 \mathrm{g} / \mathrm{mol}\). What is its molecular formula?

An organic compound has the empirical formula \(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{NO}\) If its molar mass is \(116.1 \mathrm{g} / \mathrm{mol}\), what is the molecular formula of the compound?

Acetylene is a colorless gas used as a fuel in welding torches, among other things. It is \(92.26 \%\) C and \(7.74 \%\) H. Its molar mass is \(26.02 \mathrm{g} / \mathrm{mol} .\) What are the empirical and molecular formulas of acetylene?

A large family of boron-hydrogen compounds has the general formula \(\mathrm{B}_{x} \mathrm{H}_{y}\). One member of this family contains \(88.5 \%\) B; the remainder is hydrogen. Which of the following is its empirical formula: \(\mathrm{BH}_{2}, \mathrm{BH}_{3}, \mathrm{B}_{2} \mathrm{H}_{5}, \mathrm{B}_{5} \mathrm{H}_{7}\) or \(\mathrm{B}_{5} \mathrm{H}_{11} ?\)

Cumene is a hydrocarbon, a compound composed only of \(\mathrm{C}\) and \(\mathrm{H}\). It is \(89.94 \%\) carbon, and its molar mass is 120.2 g/mol. What are the empirical and molecular formulas of cumene?

Nitrogen and oxygen form a series of oxides with the general formula \(\mathrm{N}_{x} \mathrm{O}_{y}\). One of them, a blue solid, contains \(36.84 \% N .\) What is the empirical formula of this oxide?

Mandelic acid is an organic acid composed of carbon \((63.15 \%),\) hydrogen \((5.30 \%),\) and oxygen \((31.55 \%) .\) Its molar mass is \(152.14 \mathrm{g} / \mathrm{mol}\). Determine the empirical and molecular formulas of the acid.

Nicotine, a poisonous compound found in tobacco leaves, is \(74.0 \%\) C, \(8.65 \%\) H, and \(17.35 \%\) N. Its molar mass is \(162 \mathrm{g} / \mathrm{mol} .\) What are the empirical and molecular formulas of nicotine?

If Epsom salt, \(\mathrm{MgSO}_{4} \cdot x \mathrm{H}_{2} \mathrm{O},\) is heated to \(250^{\circ} \mathrm{C},\) all the water of hydration is lost. On heating a 1.687 -g sample of the hydrate, \(0.824 \mathrm{g}\) of \(\mathrm{MgSO}_{4}\) remains. How many molecules of water occur per formula unit of \(\mathrm{MgSO}_{4} ?\)