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Solutions to Law of Chemical Equilibrium
1.
a. K= [Ag(NH3)2+1]/([Ag+1][NH3]2)
2.
TRIAL |
K ( at 900 C) so it should give the same value |
1 |
1.29 |
2 |
1.29 |
3 |
1.29 |
3.
[Cu+1]2/[Cu+2] = 1 X 10-6
Isolating for [Cu+2], the reactant, we obtain:
[Cu+2] =1 000 000[Cu+1]2 . So obviously there is a lot more reactant.
4.
D
5.
K = 0.020
6.
3A = 2B + C
Substance |
A |
B |
C |
Initial moles/L |
5.0/1 =5 |
0 |
0 |
changing moles/L |
5 – 4 = 1.0 |
B/A = 2/3, so B = (2/3)*1.0 = 0.67 |
C/A = 1/3, so C = (1/3)*1.0 = 0.33 |
moles/L at equilibrium |
4.0 /1=4 |
0.67 |
0.33 |
a. From table, B = 0.67 moles/L(1.0 L) = 0.67 moles and C = 0.33 moles/L(1.0 L) = 0.33 moles.
Substance |
A |
B |
C |
Initial moles/L |
5.0 moles/1.0 L |
0 |
0 |
changing moles/L |
5 – 2 = 3.0 |
B/A = 2/3, so B = (2/3)*3.0 = 2.0 |
C/A = 1/3, so C = (1/3)*3.0 = 1.0 |
moles/L at equilibrium |
2.0/1.0L |
2.0 |
1.0 |
7.
2 NH3 = 3 H2 + N2
Substance |
NH3 |
H2 |
N2 |
Initial moles/L |
5.0/2.0 = 2.5 |
0 |
0 |
changing moles/L |
NH3/H2 = 2/3, so NH3 = 2/3( 0.75) = 0.50 |
1.5/2.0 L = 0.75 moles/L |
0.5 /2.0 L = 0.25 moles/L |
moles/L at equilibrium |
2.5 - 0.50 = 2.0 |
1.5/2.0 L = 0.75 moles/L |
0.5/2.0 L = 0.25 moles/L |
K = [H2]3[N2]/[NH3]2 = [0.75]3[0.25]/[2.0 ]2 = 0.026
b. 2 NH3 = 3 H2 + N2
Substance |
NH3 |
H2 |
N2 |
Initial moles/L |
4.0/2.0L = 2.0 |
0 |
0 |
changing moles/L |
1.5/2.0 = 0.75 moles/L |
H2/ NH3 =3/2 , so H2 =3/2 (0.75) = 1.125 |
N2/ NH3 =1/2, so N2 = ½(0.75) = 0.375 |
moles/L at equilibrium |
2.0 - 0.75 = 1.25 |
1.125 | 0.375 |
[N2] = 0.375 moles/L
n = CV
=0.375 moles/L (2.0 L) = 0.75 moles
K = [H2]3[N2]/[NH3]2 = [1.125]3[0.375]/[1.25 ]2 = 0.34
8.a. 3A = 2B + C
Substance |
A |
B |
C |
Initial moles/L |
8.0 |
0 |
0 |
changing moles/L |
A/B = 3/2, so A = (3/2)* 4.0= 6.0 |
4.0 |
2.0 |
moles/L at equilibrium |
8.0 - 6.0 = 2.0 |
4.0 |
2.0 |
K = [B]2[C]/[A]3 = [4.0 ]2[2.0 ]/[ 2.0 ]3 = 4.0.
b. 3A = 2B + C
Substance |
A |
B |
C |
Initial moles/L |
16/2.0 L= 8 |
0 |
0 |
changing moles/L |
8– 2.0 = 6.0 |
B/A = 2/3, so B = (2/3)* 6.0 = 4.0 |
C/A = 1/3, so C = (1/3)*6.0= 2.0 |
moles/L at equilibrium |
4.0/2 = 2.0 |
4.0 |
2.0 |
K = [B]2[C]/[A]3 = [4.0]2[2.0]/[2.0 ]3 = 4.0.
Temperature was identical! Same K was obtained.
Answers for #s 9 and 10 and extra practice 11--> 15