TitrationsTitrationsHomework SolutionsHomework SolutionsPage 602Page 602

Class Example:Class Example:

NaOHNaOH(aq)(aq) + CH + CH33COOHCOOH(aq)(aq) NaCH NaCH33COOCOO(aq)(aq) + H + H22OO(l)(l)

0.500 mol/L0.500 mol/L 15.00mL15.00mL

7.5 mL7.5 mL C = ?C = ?

nnNaOHNaOH = Cv = (0.500 mol/L)(0.0075L) = 0.00375 mol = Cv = (0.500 mol/L)(0.0075L) = 0.00375 mol

nnCHCH33COOHCOOH = (0.00375 mol) (1:1 ratio) = (0.00375 mol) (1:1 ratio)

[CH[CH33COOH]COOH] = 0.00375 mol/0.015 L = 0.25 mol/L = 0.00375 mol/0.015 L = 0.25 mol/L

Practice Problems, Page 602:Practice Problems, Page 602:

#17)#17)

HNOHNO3(aq)3(aq) + NaOH + NaOH(aq)(aq) NaNO NaNO3(aq)3(aq) + H + H22OO(l)(l)

17.85 mL17.85 mL 25.00mL25.00mL

0.150 mol/L0.150 mol/L

nnNaOHNaOH = Cv = (0.025 mol/L)(0.150 L) = 0.00375 mol = Cv = (0.025 mol/L)(0.150 L) = 0.00375 mol

nnHNOHNO33 = 0.00375 mol 1:1 ratio = 0.00375 mol 1:1 ratio

[[HNOHNO33]] = 0.00375 mol/0.01785 L = 0.210 mol/L = 0.00375 mol/0.01785 L = 0.210 mol/L

Practice Problems, Page 602:Practice Problems, Page 602:#18)#18)Mg(OH)Mg(OH)2(aq)2(aq) + 2HCl + 2HCl(aq)(aq) MgCl MgCl2(aq)2(aq) + 2H + 2H22OO(l)(l)

1.015 mol/L1.015 mol/L 40.00mL40.00mL 1.60 mol/L1.60 mol/L

nnHClHCl = Cv = (1.60 mol/L)(0.04 L) = 0.064 mol = Cv = (1.60 mol/L)(0.04 L) = 0.064 molnnMg(OH)Mg(OH)22

= 0.064 mol HCl X = 0.064 mol HCl X 1 Mg(OH)1 Mg(OH)2 2 = 0.032 mol Mg(OH)= 0.032 mol Mg(OH)22

2 HCl2 HCl[Mg(OH)[Mg(OH)22] = 1.015 mol/L] = 1.015 mol/LVVMg(OH)Mg(OH)22

= = n n = = 0.032 mol 0.032 mol = 0.0315 L = 31.5 mL = 0.0315 L = 31.5 mL c 1.015 mol/Lc 1.015 mol/L

Practice Problems, Page 602:Practice Problems, Page 602:

19a)19a)HClHCl(aq)(aq) + NaOH + NaOH(aq)(aq) NaCl NaCl(aq)(aq) + H + H22OO(l)(l)

0.150 M0.150 M 25.00mL25.00mL 0.135 mol/L0.135 mol/L

nnNaOHNaOH = Cv = (0.135 mol/L)(0.025 L) = 0.003375 mol NaOH = Cv = (0.135 mol/L)(0.025 L) = 0.003375 mol NaOHnnHClHCl = 0.003375 mol HCl (1:1 ratio) = 0.003375 mol HCl (1:1 ratio) VVHClHCl = = n n = = 0.003375 mol 0.003375 mol = 0.0225 L = 22.5 mL = 0.0225 L = 22.5 mL

c 0.150 mol/Lc 0.150 mol/L

Practice Problems, Page 602:Practice Problems, Page 602:

b)b)HClHCl(aq)(aq) + NH + NH3(aq)3(aq) NH NH44ClCl(aq)(aq) 0.150 M0.150 M 20.00mL20.00mL

0.185 mol/L0.185 mol/L

nnNHNH33 = Cv = (0.185 mol/L)(0.02 L) = 0.0037 mol NaOH = Cv = (0.185 mol/L)(0.02 L) = 0.0037 mol NaOH

nnHClHCl = 0.0037 mol (1:1 ratio) = 0.0037 mol (1:1 ratio) VVHClHCl = = n n = = 0.0037 mol 0.0037 mol = 0.02467 L = 24.7 mL = 0.02467 L = 24.7 mL

c 0.150 mol/Lc 0.150 mol/L

Practice Problems, Page 602:Practice Problems, Page 602:c)c)2HCl2HCl(aq)(aq) + Ca(OH) + Ca(OH)2(aq)2(aq) 2H 2H22OO(l) (l) + CaCl+ CaCl2(aq)2(aq) 0.150 M0.150 M 80.00mL80.00mL

0.0045 mol/L0.0045 mol/L

nnCa(OH)Ca(OH)22 = Cv = (0.0045 mol/L)(0.08 L) = 3.6 X 10 = Cv = (0.0045 mol/L)(0.08 L) = 3.6 X 10-4-4 mol mol

nnHClHCl = 3.6 X 10 = 3.6 X 10-4-4 mol Ca(OH) mol Ca(OH)2 2 X X 2 HCl2 HCl = 7.2 X 10= 7.2 X 10-4-4 mol HCl mol HCl 1 Ca(OH)1 Ca(OH)22

VVHClHCl = = n n = = 7.2 X 107.2 X 10-4 -4 mol mol = 0.0048 L = 4.80 mL = 0.0048 L = 4.80 mL c 0.150 mol/Lc 0.150 mol/L

Practice Problems, Page 602:Practice Problems, Page 602:20a)20a)NaOHNaOH(aq)(aq) + HF + HFaq)aq) H H22OO(l) (l) + NaF+ NaF(aq)(aq) 37.82mL37.82mL 15.00mL15.00mL

0.250 mol/L0.250 mol/L

nnHFHF= Cv = (0.250 mol/L)(0.015 L) = 0.00375mol = Cv = (0.250 mol/L)(0.015 L) = 0.00375mol

nnNaOHNaOH= 0.00375 mol (1:1 ratio)= 0.00375 mol (1:1 ratio)

[NaOH] = [NaOH] = n n = = 0.003750.00375 mol mol = 0.09915 L = 0.09915 L 0.0992 mol/L 0.0992 mol/L

V 0.03782 LV 0.03782 L

Practice Problems, Page 602:Practice Problems, Page 602:b)b)2NaOH2NaOH(aq)(aq) + H + H22SOSO4(aq)4(aq) Na Na22SOSO4(aq) 4(aq) + 2H+ 2H22OO(l) (l)

21.56 mL21.56 mL 20.00mL20.00mL 0.145 mol/L0.145 mol/L

nnHH22SOSO44 = Cv = (0.145 mol/L)(0.02 L) = 0.0029 mol = Cv = (0.145 mol/L)(0.02 L) = 0.0029 mol

nnNaOHNaOH= 0.0029 mol H= 0.0029 mol H22SOSO4 4 X X 2 NaOH2 NaOH = 0.0058 mol NaOH= 0.0058 mol NaOH 1 H1 H22SOSO44

[NaOH] = [NaOH] = n n = = 0.00580.0058 mol mol = 0.269 mol/L = 0.269 mol/L c 0.02156 Lc 0.02156 L

Practice Problems, Page 602:Practice Problems, Page 602:c)c)3NaOH3NaOH(aq)(aq) + H + H33POPO4(aq)4(aq) Na Na33POPO4(aq) 4(aq) + 3H+ 3H22OO(l) (l)

14.27 mL14.27 mL 25.00mL25.00mL 0.105 mol/L0.105 mol/L

nnHH33POPO44 = Cv = (0.105 mol/L)(0.025 L) = 0.00262 mol = Cv = (0.105 mol/L)(0.025 L) = 0.00262 mol

nnNaOHNaOH= 0.00262 mol H= 0.00262 mol H33POPO4 4 X X 3 NaOH3 NaOH = 0.007875 mol NaOH= 0.007875 mol NaOH 1 H1 H33POPO44

[NaOH] = [NaOH] = n n = = 0.0078750.007875 mol mol = 0.550 mol/L = 0.550 mol/L c 0.01427 Lc 0.01427 L