chapter 3 textbook questions

A sugar crystal contains approximately 1.8 * 1017 sucrose (C12H22O11) molecules. What is its mass in mg?

0.10 mg

What is the mass of a sample of water containing 3.55 * 1022 H2O molecules?

1.06 g H2O

An aspirin tablet contains 325 mg of acetylsalicylic acid (C9H8O4) . How many acetylsalicylic acid molecules does it contain?

1.09 * 1021 C9H8O4 molecules

Calculate the formula mass of calcium nitrate

164.10 amu

Calculate the formula mass of glucose, C6H12O6 .

180.16 amu

The iodide ion is a dietary mineral essential to good nutrition. In countries where potassium iodide is added to salt, iodine deficiency (or goiter) has been almost completely eliminated. The recommended daily allowance (RDA) for iodine is 150 mg/day . How much potassium iodide (76.45% I) should you consume if you want to meet the RDA?

196 mg KI

Write a balanced equation for the combustion of gaseous ethane (C2H6), a minority component of natural gas, in which it combines with gaseous oxygen to form gaseous carbon dioxide and gaseous water.

2 C2H6(g) + 7 O2(g)-->4 CO2(g) + 6 H2O(g)

Write a balanced equation for the combustion of gaseous butane (C4H10), a fuel used in portable stoves and grills, in which it combines with gaseous oxygen to form gaseous carbon dioxide and gaseous water.

2 C4H10(g) + 13 O2(g) --> 8 CO2(g) + 10 H2O(g)

Write a balanced equation for the reaction between solid cobalt(III) oxide and solid carbon to produce solid cobalt and carbon dioxide gas.

2 Co2O3(s) + 3 C(s) --> 4 Co(s) + 3 CO2(g)

Copper(II) fluoride contains 37.42% F by mass. Calculate the mass of fluorine (in g) contained in 55.5 g of copper(II) fluoride

20.8 g F

Write a balanced equation for the reaction between aqueous strontium chloride and aqueous lithium phosphate to form solid strontium phosphate and aqueous lithium chloride.

3 SrCl2(aq) + 2 Li3PO4(aq) --> Sr3(PO4)2(s) + 6 LiCl(aq)

Butane (C4H10) is the liquid fuel in lighters. How many grams of carbon are present within a lighter containing 7.25 mL of butane? (The density of liquid butane is 0.601 g>mL.)

3.60 g C

Determine the mass of oxygen in a 7.2 g sample of Al2(SO4)3

4.0 g O

Hydrogen may potentially be used in the future to replace gasoline as a fuel. Most major automobile companies are developing vehicles that run on hydrogen. These cars are environmentally friendly because their only emission is water vapor. One way to obtain hydrogen for fuel is to use an emission-free energy source such as wind power to form elemental hydrogen from water. What mass of hydrogen (in grams) is contained in 1.00 gallon of water? (The density of water is 1.00 g>mL.)

4.23 * 102 g H

Find the number of ibuprofen molecules in a tablet containing 200.0 mg of ibuprofen (C13H18O2) .

5.839 * 1020 C13H18O2 molecules

Acetic acid (C2H4O2) is the active ingredient in vinegar. Calculate the mass percent composition of oxygen in acetic acid.

53.29%

The U.S. Food and Drug Administration (FDA) recommends that a person consume less than 2.4 g of sodium per day. What mass of sodium chloride (in grams) can you consume and still be within the FDA guidelines? Sodium chloride is 39% sodium by mass.

6.2 g NaCl

Calculate the mass percent of Cl in Freon-112 (C2Cl4F2) , a CFC refrigerant

69.58%

Calculate the mass percent composition of sodium in sodium oxide.

74.19% Na

If someone consumes 22 g of sodium chloride per day, what mass (in grams) of sodium does that person consume? Sodium chloride is 39% sodium by mass.

8.6 g Na

What mass (in grams) of iron(III) oxide contains 58.7 grams of iron? Iron(III) oxide is 69.94% iron by mass.

83.9 g Fe2O3

Write the formula for the ionic compound that forms between aluminum and oxygen.

Al2O3

Write the formula for the compound formed between aluminum and nitrogen.

AlN

Upon combustion, a 0.8233 g sample of a compound containing only carbon, hydrogen, and oxygen produces 2.445 g CO2 and 0.6003 g H2O. Find the empirical formula of the compound.

C10H12O1

Ibuprofen has the following mass percent composition: C 75.69%, H 8.80%, O 15.51%. What is the empirical formula of ibuprofen?

C13H18O2

Upon combustion, a 0.8009 g sample of a compound containing only carbon, hydrogen, and oxygen produced 1.6004 g CO2 and 0.6551 g H2O. Find the empirical formula of the compound.

C2H4O

Upon combustion, a compound containing only carbon and hydrogen produced 1.60 g CO2 and 0.819 g H2O. Find the empirical formula of the compound.

C2H5

A compound with the percent composition shown next has a molar mass of 60.10 g>mol. Determine its molecular formula. C, 39.97% H, 13.41% N, 46.62%

C2H8N2

Butanedione—a main component responsible for the smell and taste of butter and cheese—contains the elements carbon, hydrogen, and oxygen. The empirical formula of butanedione is C2H3O , and its molar mass is 86.09 g>mol. Find its molecular formula.

C4H6O2

Upon combustion, a compound containing only carbon and hydrogen produces 1.83 g CO2 and 0.901 g H2O. Find the empirical formula of the compound.

C5H12.

A compound has the empirical formula CH and a molar mass of 78.11 g>mol. What is its molecular formula?

C6H6

A laboratory analysis of aspirin determined the following mass percent composition: C 60.00% H 4.48% O 35.52% Find the empirical formula.

C9H8O4

A sample of a compound is decomposed in the laboratory and produces 165 g carbon, 27.8 g hydrogen, and 220.2 g oxygen. Calculate the empirical formula of the compound.

CH2O

Write the formula for the ionic compound that forms between calcium and oxygen.

CaO

Write the formula for cobalt(II) phosphate

Co3(PO4)2

Write the formula for perchloric acid.

HClO4

Write the formula for the compound formed between potassium and sulfur.

K2S

A compound containing nitrogen and oxygen is decomposed in the laboratory and produces 24.5 g nitrogen and 70.0 g oxygen. Calculate the empirical formula of the compound.

N2O5

Most fertilizers consist of nitrogen-containing compounds such as NH3 , CO(NH2)2 , NH4NO3 , and (NH4)2SO4 . The nitrogen content in these compounds is used for protein synthesis by plants. Calculate the mass percent composition of nitrogen in each of the fertilizers named. Which fertilizer has the highest nitrogen content?

NH3: 82.27% N CO(NH2)2: 46.65% N NH4NO3: 35.00% N (NH4)2SO4: 21.20% N NH3 has the highest N content

Write the formula for phosphorus tribromide.

PBr3

Write a balanced equation for the reaction between aqueous lead(II) nitrate and aqueous potassium chloride to form solid lead(II) chloride and aqueous potassium nitrate.

Pb(NO 3 ) 2 (aq) + 2 KCl(aq)--> PbCl 2 (s) + 2 KNO 3 (aq)

Write the formula for rubidium sulfide.

Rb2S

Write the formula for ruthenium(IV) oxide

RuO2

Write a balanced equation for the reaction between solid silicon dioxide and solid carbon to produce solid silicon carbide and carbon monoxide gas.

SiO2(s) + 3 C(s)-->SiC(s) + 2 CO(g)

Name the compound SrI2 . a) strontium iodide b) strontium diiodide c) strontium(II) iodide d) strontium(II) diiodide

a

What are the correct coeffi cients (reading from left to right) when the chemical equation is balanced? __PCl3(l) + __H2O(l) S __H3PO3(aq) + __HCl(aq) a) 1, 3, 1, 3 b) 1, 2, 1, 1 c) 1, 3, 2, 1 d) 3, 6, 1, 9

a

What is the correct formula for the compound formed between calcium and sulfur? a) CaS b) Ca2S c) CaS2 d) CaS3

a

Which substance is an ionic compound? a) SrI2 b) N2O4 c) He d) CCl4

a

Write empirical formulas for the compounds represented by the molecular formulas. (a) C4H8 (b) B2H6 (c) CCl4

a) CH2 b)BH3 c) CCl4

Classify each of the substances as an atomic element, molecular element, molecular compound, or ionic compound. (a) xenon (b) NiCl2 (c) bromine (d) NO2 (e) NaNO3

a) atomic element b) ionic compound c) molecular element d) molecular compound e) ionic coupound

Name each compound. (a) NI3 (b) PCl5 (c) P4S10

a) nitrogen triiodide b) phosporus pentachloride c) tetraphosphorus decasulfide

Calculate the mass (in g) of each sample. a. 5.94 * 1020 SO3 molecules b. 2.8 * 1022 H2O molecules c. 1 glucose molecule (C6H12O6)

a. 0.0790 g b. 0.84 g c. 2.992 * 10-22 g

Calculate the number of moles in each sample. a. 72.5 g CCl 4 b. 12.4 g C 12 H 22 O 11 c. 25.2 kg C 2 H 2 d. 12.3 g of dinitrogen monoxide

a. 0.471 mol b. 0.0362 mol c. 968 mol d. 0.279 mol

Determine the number of moles (of molecules or formula units) in each sample. a. 25.5 g NO2 b. 1.25 kg CO2 c. 38.2 g KNO3 d. 155.2 kg Na2SO4

a. 0.554 mol b. 28.4 mol c. 0.378 mol d. 1093 mol

Determine the number of moles of hydrogen atoms in each sample. a. 0.0885 mol C4H10 b. 1.3 mol CH4 c. 2.4 mol C6H12 d. 1.87 mol C8H18

a. 0.885 mol H b. 5.2 mol H c. 29 mol H d. 33.7 mol H

How many molecules are in each sample? a. 6.5 g H2O b. 389 g CBr4 c. 22.1 g O2 d. 19.3 g C8H10

a. 2.2 * 1023 molecules b. 7.06 * 1023 molecules c. 4.16 * 1023 molecules d. 1.09 * 1023 molecules

Determine the number of each type of atom in each formula: a. Mg3(PO4)2 b. BaCl2 c. Fe(NO2)2 d. Ca(OH)2

a. 3 Mg, 2 P, 8 O b. 1 Ba, 2 Cl c. 1 Fe, 2 N, 4 O d. 1 Ca, 2 O, 2 H

Calculate mass (in grams) of sodium in 8.5 g of each sodium containing food additive. a. NaCl (table salt) b. Na3PO4 (sodium phosphate) c. NaC7H5O2 (sodium benzoate) d. Na2C6H6O7 (sodium hydrogen citrate)

a. 3.3 g Na b. 3.6 g Na c. 1.4 g Na d. 1.7 g Na

Calculate the formula mass for each compound. a. NO2 b. C4H10 c. C6H12O6 d. Cr(NO3)3

a. 46.01 amu b. 58.12 amu c. 180.16 amu d. 238.03 amu

Calculate the mass percent composition of carbon in each carbon-containing compound. a. CH4 b. C2H6 c. C2H2 d. C2H5Cl

a. 74.87% C b. 79.88% C c. 92.24% C d. 37.23% C

A chemist decomposes samples of several compounds; the masses of their constituent elements are shown below. Calculate the empirical formula for each compound. a. 1.651 g Ag, 0.1224 g O b. 0.672 g Co, 0.569 g As, 0.486 g O c. 1.443 g Se, 5.841 g Br

a. Ag2O b. Co3As2O8 c. SeBr4

Write the empirical formula for the compounds represented by the molecular formulas. (a) C5H12 (b) Hg2Cl2 (c) C2H4O2

a. C5H12 b. HgCl c. CH2O

Write a formula for the compound that forms between calcium and each polyatomic ion. a. hydroxide b. chromate c. phosphate d. cyanide

a. Ca(OH) 2 b. CaCrO4 c. Ca3(PO4)2 d. Ca(CN)2

Write a formula for the ionic compound that forms between each pair of elements. a. calcium and oxygen b. zinc and sulfur c. rubidium and bromine d. aluminum and oxygen

a. CaO b. ZnS c. RbBr d. Al2O3

Write formulas for each acid. a. hydrofluoric acid b. hydrobromic acid c. sulfurous acid

a. HF b. HBr c. H2SO3

Write a formula for each ionic compound. a. sodium hydrogen sulfite b. lithium permanganate c. silver nitrate d. potassium sulfate e. rubidium hydrogen sulfate f. potassium hydrogen carbonate

a. NaHSO3 b. LiMnO4 c. AgNO3 d. K2SO4 e. RbHSO4 f. KHCO3

Write a formula for each molecular compound. a. phosphorus trichloride b. chlorine monoxide c. disulfur tetrafluoride d. phosphorus pentafluoride

a. PCl3 b. ClO c. S2F4 d. PF5

Classify each element as atomic or molecular. a. neon b. fluorine c. potassium d. nitrogen

a. atomic b. molecular c. atomic d. molecular

Name each molecular compound. a. CO b. NI3 c. SiCl4 d. N4Se4

a. carbon monoxide b. nitrogen triiodide c. silicon tetrachloride d. tetranitrogen tetraselenide

Write the name from the formula or the formula from the name for each hydrated ionic compound. a. CoSO4 # 7H2O b. iridium(III) bromide tetrahydrate c. Mg(BrO3)2 # 6H2O

a. cobalt(II) sulfate heptahydrate b. IrBr3 # 4 H2O c. Magnesium bromate hexahydrate d. K2CO3 # 2 H2O

Name each ionic compound containing a polyatomic ion. a. CuNO2 b. Mg(C2H3O2)2 c. Ba(NO3)2 d. Pb(C2H3O2)2

a. copper(I) nitrite b. magnesium acetate c. barium nitrate d. lead(II) acetate

Name each acid. a. HI( aq ) b. HNO3 ( aq ) c. H2CO3 ( aq )

a. hydroiodic acid b. nitric acid c. carbonic acid

Name each ionic compound. a. Mg3N2 b. KF c. Na2O d. Li2S e. CsF f. KI

a. magnesium nitride b. potassium fluoride c. sodium oxide d. lithium sulfide e. cesium fluoride f. potassium iodide

Classify each compound as ionic or molecular. a. CO2 b. NiCl2 c. NaI d. PCl3

a. molecular b. ionic c. ionic d. molecular

Classify each of the substances as an atomic element, molecular element, molecular compound, or ionic compound. (a) fluorine (b) N2O (c) silver (d) K2O (e) Fe2O3

a. molecular element b. molecular compound c. atomic element d. ionic compound e. ionic compound

name each compound. a. KClO 3 b. I 2 O 5 c. PbSO 4

a. potassium chlorate b. diiodine pentoxide c. lead(II) sulfate

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. SrCl 2 b. SnO 2 c. P 2 S 5 d. HC 2 H 3 O 2( aq )

a. strontium chloride b. tin(IV) oxide c. diphosphorus pentasulfide d. acetic acid

Give each ionic compound an appropriate name. a. SnO b. Cr2S3 c. RbI d. BaBr2

a. tin(II) oxide b. chromium(III) sulfide c. rubidium iodide d. barium bromide

Name HC2H3O2(aq) .

acetic acid

A compound is 52.14% C, 13.13% H, and 34.73% O by mass. What is the empirical formula of the compound? a) C2H8O3 b) C2H6O c) C4HO3 d) C3HO6

b

Combustion of 30.42 g of a compound containing only carbon, hydrogen, and oxygen produces 35.21 g CO2 and 14.42 g H2O. What is the empirical formula of the compound? a) C4H8O6 b) C2H4O3 c) C2H2O3 d) C6HO12

b

Determine the number of CH2Cl2 molecules in 25.0 g CH2Cl2 . a) 0.294 molecules b) 1.77 * 10^23 molecules c) 1.28 * 10^27 molecules d) 1.51 * 10^25 molecules

b

List the elements in the compound CF2Cl2 in order of decreasing mass percent composition. a) C 7 F 7 Cl b) F 7 Cl 7 C c) Cl 7 C 7 F d) Cl 7 F 7 C

b

Name the compound Pb(C2H3O2)2 . a) lead(II) carbonate b) lead(II) acetate c) lead bicarbonate d) lead diacetate

b

Determine the mass of potassium in 35.5 g of KBr. a) 17.4 g b) 0.298 g c) 11.7 g d) 32.9 g

c

What is the empirical formula of a compound with the molecular formula C10H8? a) C5H3 b) C2H4 c) C5H4 d) CH

c

Name the compound CaBr2

calcium bromide

A compound has the empirical formula CH2O and a formula mass of 120.10 amu. What is the molecular formula of the compound? a) CH2O b) C2H4O2 c) C3H6O3 d) C4H8O4

d

Name the compound HNO2( aq ). a) hydrogen nitrogen dioxide b) hydrogen nitrate c) nitric acid d) nitrous acid

d

Name the compound P2I4 . a) phosphorus iodide b) phosphorus diiodide c) phosphorus(II) iodide d) diphosphorus tetraiodide

d

What is the formula for manganese(IV) oxide? a) Mn4O b) MnO4 c) Mn2O d) MnO2

d

Name the compound N2O5 .

dinitrogen pentoxide

Name HF( aq ).

hydrofluoric acid

Name HI( aq ).

hydroiodic acid

Name the compound FeS.

iron(II) sulfide

Name the compound PbCl4

lead(IV) chloride

Name the compound Li2Cr2O7 .

lithium dichromate

Name HNO2(aq) .

nitrous acid

Name the compound Ag3N .

silver nitride

Name the compound Sn(ClO3)2 .

tin(II) chlorate