Selected Solutions to the Exercises in the Chem 161 lab manual
page A-3
a) 5.4x103; b) 2.987x10-7; c) 3.0004x104; d)
0.00000598; e) 4,000; f) 85; g) 10x10-8 or 1x10-7; h)
8x10-33; i) 2x103
page A-4
a) 0.385 mL
±0.001 mL; b) 254.3 g ±0.1 g; c) 0.032
m ± 0.001 m; d) 31 L ± 1 L;
e) 0.0099 kg ± 0.0001 kg; f)
550 μm
± 10 µm; g) 3; h) 4; i) 2; j) 3; k) 2; l) 3
page A-5
a)30.5 mL; b) 1.03 mL;
c)2.3x10-6 mol
page A-6
a) 1.5x106 mm; b) 3.0x1015 mg; c) 0.5 L; d)0.05000 km; e)
4x1011 µm
page A-7 (solutions are provided
at the bottom of page A-7)
page A-8 through A10
Part 1: a) 74.8 kg; b) 7.458 mol Ne; c) 4.60 x 103 cm
Part 2: a) 105 km (rounded to 110 km); b) 3.02x1023 Al atoms
Part 3: a) (3ft)3 = 9 ft3; b) 1340 lb/ft3
page A-12
NaCl/NaHCO3/Na3PO4/Na2CO3/Na2S/NaOH
FeCl3/Fe(HCO3)3/FePO4/Fe2(CO3)3/Fe2S3/Fe(OH)3
CaCl2/Ca(HCO3)2/Ca3(PO4)2/CaCO3/CaS/Ca(OH)2
SnCl4/Sn(HCO3)4/Sn3(PO4)4/Sn(CO3)2/SnS2/Sn(OH)4
ZnCl2/Zn(HCO3)2/Zn3(PO4)2/ZnCO3/ZnS/Zn(OH)2
1) CsI; 2) Li2SO4; 3) CoCO3;
4) Zn3N2; 5) Mg3(PO4)2;
6) (NH4)C2O4; 7) NaBr;
8) Fe(CN)2; 9) CuCl2; 10) Be(NO3)2;
11) Ca(NO2)2; 12) SnF2; 13) K2S;
14) Ag2O; 15) Al(HCO3)3; 16) Zn(OH)2;
17) Cr2O3; 18) PbBr4; 19) NiSO4;
20) Al(NO2)3
page A-13
1) beryllium sulfide; 2) calcium hydride; 3) sodium iodide; 4) magnesium oxide;
5) aluminum bromide (not tribromide!); 6) lithium sulfide; 7) zinc fluoride (not zinc (II) fluoride!); 8)
potassium nitride; 9) silver chloride; 10) aluminum nitride; 11) beryllium
chloride; 12) calcium iodide; 13) magnesium bromide; 14) silver sulfide; 16)
zinc oxide; 17) ammonium bromide; 18) aluminum hydroxide; 19) lithium
phosphate; 20) magnesium acetate; 21) zinc bisulfate or zinc hydrogen sulfate;
22) ammonium carbonate; 23) sodium chlorate; 24) calcium cyanide; potassium
bicarbonate or potassium hydrogen carbonate; 26) magnesium phosphate; 27)
aluminum nitrite; 28) silver sulfate; 29) chromium (III) oxide; 30) cobalt
(III) nitride; 31) iron (III) iodide; 32) cobalt (II) bisulfate or cobalt (II)
hydrogen sulfate; 33) copper (I) oxide; 34) mercury (II) chlorate; 35) nickel
(II) bromide; 36) copper (II) sulfite; 37) nickel (III) nitrate; 38) iron (II)
acetate
page A-14 (solutions are
provided on A-15)
page A-17
1) a) 386.66 g/mol (using 3 decimals on
molar masses); b) 83.871% C by mass; c) 4.21x1020 cholesterol
molecules and 1.14x1022 carbon atoms
2) 65,300 g/mol
3) C6H8O6 (molecular) and C3H4O3
(empirical)
page A-18
(1) 1, 1, 2; (2) 2, 1, 2; (3) 1, 2, 2; 4) 2, 2, 1; (5) 1, 2, 1, 1; (6) 1, 1, 1,
1; (7) 1, 3, 2; (8) 1, 12, 12, 11; (9) 1, 4, 1, 6; (10) 1, 1, 1, 2
11) 4 Al (s) + 3 O2 (g) → 2 Al2O3 (s)
12) Na(s) + H2O (l) → NaOH (aq) + H2 (g)
13) 4 KMnO4 (aq) → 2 K2O
(aq) + 4 MnO (aq) + 5 O2 (g)
14) H2SO4 (aq) + 2 NaOH (aq) → Na2SO4
(aq) + 2 H2O (l)
15) Cu (s) + 2 AgNO3 (aq) → 2 Ag (s)
+ Cu(NO3)2 (aq)
page A-19
1) 39.9 g CS2;
2a) Sulfur, b) 39.9 g CS2, c) 15.6 g CH4 in excess
3a) C2H2 (g) + 2 H2 (g) → C2H6
(g); b) 30.8 g C2H6
page A-20
16.6 g of substance C is formed.
page A-23
(a) soluble, Pb2+ (aq) and CH3COO- (aq); (b) insoluble, (NH4)2S (s); (c) soluble, NH4+ (aq) and S2- (aq); (d) insoluble, AgI (s)
page A-34
1) -1300 kJ/mol P4; 2) 37.4 deg C; 3) -3760 kJ/mol; 4) exothermic, 2.35 g NaCl produced; 5a) KOH, b) 0.15 moles KOH, c) precipitate is Cu(OH)2 (s). Molecular: CuSO4 (aq) + 2KOH (aq) --> K2SO4 (aq) + Cu(OH)2 (s); Net ionic: Cu2+ (aq) + 2 OH- (aq) --> Cu(OH)2 (s); d) -17.3 kJ
page A-43
1a) orbital, b) orbital, c) shell, d) shell; 2a) 5, since shell # = # of shells, b) 5s, 5p, 5d, 5f; c) 2, 6, 10, 14; d) in the entire shell, the five subshells are 5s, 5p, 5d, 5f, and 5g (theoretically). Number of orbitals are 1+3+5+7+9 = 25. 2 electrons max per orbital: 2 x 25 = 50 electrons max, e) for the first four subshells, 1+3+5+7= 16 orbitals x 2 electrons max = 32 electrons max. 3a) false-the orbital itself doesn't have a definite size unless the shell number is given-for example, s means spherical, but 2s is larger than 1s, b) true, c) true, d) false, e) true, f) false, g) true, h) flase, i) false. 4a) 10, b) 2, c) 8, d) 32, 5) b, c, f do not exist. 6) In the notation 3d7, 3 refers to the shell number (n) which indicates the distance from the nucleus or energy of the electron, 3d refers to the subshell, d refers to the shape of the orbtial, and 7 refers to the number of electrons in the 3d subshell.