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WorksheetsAP Chemistry Equilibrium and pH
Total questions: 100
Worksheet time: 50mins
The average rate of disappearance of ozone in the reaction 2O3(g) → 3O2(g) is found to be 7.25x10-3 atm over a certain interanl of time. What is the rate of appearance of O2 during this interval?
10.9x10-3 atm/s
7.25x10-3 atm/s
4.83x10-3 atm/s
191x10-3 atm/s
17.5x10-3 atm/s
Consider the reaction: 4NH3 + 7O2 → 4NO2 + 6H2O
At a certain instant the initial rate of disappearance of the oxygen gas is X. What is the value of the appearance of water at the same instant?
1.2 X
1.1 X
0.86 X
0.58 X
cannot be determined from the data
Consider the reaction X → Y +Z
Which of the following is a possible rate law?
Rate = k[X]
Rate = k[Y]
Rate = k[Y][Z]
Rate = k[X][Y]
Rate = k[Z]
Consider the following rate law: Rate = k[A]n[B]m
How are the exponents n and m determined?
by using the balanced chemical equation
by using the subscripts for the chemical formulas
by using the coefficients of the chemical formulas
by educated guess
by experiment
The following data were obtained for the reaction of NO with O2. Concentrations are in molecules/cm3 and rates are in molecules/cm3⋅s.
Rate = k[NO][O2]
Rate = k[NO][O2]2
Rate = k[NO]2[O2]
Rate = k[NO]2
Rate = k[NO]2[O2]2
The reaction of (CH3)3CBr with hydroxide ion proceeds with the formation of (CH3)3COH.
What will the initial rate (in mol/L⋅s) be in experiment 4?
3.0x10-3
6.0x10-3
9.0x10-3
18x10-3
none of these
The table shows the initial rate data for a certain reaction. What is the value of k?
107 M-5 s-1
103 M-3 s-1
10 M-2 s-1
50 M-2 s-1
none of these
What is the order of the reaction with respect to B?
0
1
2
3
4
What is the order of the reaction with respect to A?
0
1
2
3
4
What is the overall order of the reaction?
0
1
2
3
4
What is the numerical value of the rate constant?
0.053
1.19
2.37
5.63
none of these
Determine the initial rate of B consumption (ΔB/Δt) for the first trial.
8.00x10-3 mol/L⋅s
1.60x10-2 mol/L⋅s
3.20x10-2 mol/L⋅s
4.00x10-3 mol/L⋅s
none of these
Determine the initial rate of C production (ΔC/Δt) if [A] = 0.200 M and [B] = 0.500 M.
4.74x10-2 mol/L⋅s
2.37x10-1 mol/L⋅s
1.19x10-1 mol/L⋅s
8.23x10-2 mol/L⋅s
none of these
The rate expression for a particular reaction is rate = k[A][B]2. If the initial concentration of B is increased from 0.1 M to 0.3 M, the initial rate will increase by which of the following factors?
2
6
12
3
9
These data were collected for the decay of HO2 radicals.
Which of the following best describes the reaction?
The decay of HO2 occurs by a first-order reaction.
The half-life of the reaction is 2 ms.
A plot of ln[HO2] versus time is linear with a slope of -k.
The rate of the reaction increases with time.
A plot of 1/[HO2] versus time gives a straight line.
The rate law for a given reaction is found to be Rate = k[A]2[B]. Which of the following mechanisms gives this rate law? (choose all that apply)
I
II
III
The value of the equilibrium constant, K, is dependent on:
the temperature of the system
the nature of the reactants and products
the concentration of the reactants
the concentration of the products
none of these options
If the equilibrium constant for A + B ⇆ C is 0.208, then the equilibrium constant for 2C ⇆ 2A + 2B is
0.584
4.81
0.416
23.1
0.208
If, at a given temperature, the equilibrium constant for the reaction H2(g) + Cl2(g) ⇆ 2HCl(g) is Kp, then the equilibrium constant for the reaction HCl(g) ⇆ ½H2(g) + ½Cl2(g) can be represented
Given the equilibrium constants for the following reactions:
4Cu(s) + O2(g) ⇆ 2Cu2O(s), K1
2CuO(s) ⇆ Cu2O(s) + ½O2(g), K2
what is K for the system
2Cu(s) + O2(g) ⇆ 2CuO(s)
equivalent to?
Which expression correctly describes the equilibrium constant for the following reaction?
4NH3(g) + 5O2(g) ⇆ 4NO(g) + 6H2O(g)
Consider the chemical system
CO + Cl2 ⇆ COCl2, K = 4.6x109
How do the equilibrium concentrations of the reactants compare to the equilibrium concentration of the products?
They are much smaller.
They are much larger.
They are about the same.
They have to be exactly equal.
You can't tell from the information given.
Consider the chemical system
CO + Cl2 ⇆ COCl2, K = 4.6x109
If the concentration of the product were to double, what would happen to the equilibrium constant?
It would double its value.
It would become half its current value.
It would quadruple its value.
It would not change its value.
It would depend on the initial conditions of the product.
Determine the equilibrium constant for the system N2O4 ⇆ 2NO2 at 25oC. The concentrations are shown here: [N2O4] = 2.32x10-2 M, [NO2] = 1.41x10-2 M.
0.608
1.65
1.17x102
0.369
8.57x10-3
An equilibrium reaction A2(g) + 3B2(g) ⇆ 2C(g), has a Kp at 225oC of 2.6x10-3. What is K for this reaction at that temperature?
1.6x10-6
7.6x10-6
4.3
6.4x10-5
0.89
Consider the reaction
CaCl2(s) + 2H2O(g) ⇆ CaCl2⋅2H2O(s)
The equilibrium constant for the reaction as written is:
Consider the following equilibrium: H2(g) + I2(s) ⇆ 2HI(g)
The proper Keq expression is:
Consider the following equilibrium: H2(g) + I2(s) ⇆ 2HI(g)
Which of the following statements about the equilibrium is false?
If the system is heated, the right side is favored.
This is a heterogeneous equilibrium.
If the pressure on the system is increased by changing the volume, the left side is favored.
Adding more H2(g) increases the equilibrium constant.
Removing HI as it forms forces the equilibrium to the right.
Consider the reaction: 2SO2(g) + O2(g) ⇆ 2SO3(g) at constant temperature. Initially a container is filled with pure SO3(g) at a pressure of 2 atm, after which equilibrium is reached. If y is the partial pressure of O2 at equilibrium, the value of Kp is:
None of these
A 10.0-g sample of solid NH4Cl is heated in a 5.00-L container to 900.oC. At equilibrium the pressure of NH3(g) is 1.51 atm.
NH4Cl(s) ⇆ NH3(g) + HCl(g)
The equilibrium constant, Kp, for the reaction is:
1.51
2.28
3.02
8.21
none of these
Consider the reaction H2 + I2 ⇆ 2HI for which K = 44.8 at a high temperature. If an equimolar mixture of reactants gives the concentration of the product to be 0.50 M at equilibrium, determine the equilibrium concentration of the hydrogen.
1.1x10-1 M
7.5x10-2 M
3.7x10-2 M
13 M
5.6x10-3 M
Consider the equation A(aq) + 2B(aq) ⇆ 3C(aq) + 2D(aq). In one experiment, 45.0 mL of 0.050 M A is mixed with 25.0 mL 0.100 M B. At equilibrium the concentration of C is 0.0410 M. Calculate K.
7.3
0.34
0.040
0.14
none of these
For the equilibrium that exists in an aqueous solution of nitrous acid (HNO2, a weak acid), the equilibrium constant expression is:
None of these
The following three equation represent equilibria that lie far to the right.
Identify the strongest acid.
HCN
HNO3
H2O
OH-
CH3OH
The following three equation represent equilibria that lie far to the right.
Identify the strongest base.
CH3O-
CH3OH
CH-
H2O
NO3-
A solution in which the pOH is 12.1 would be described as
very acidic
slightly acidic
neutral
very basic
slightly basic
Calculate the [H+] in a solution that has a pH of 9.88.
4.1 M
9.9 M
7.6x10-5 M
1.3x10-10 M
none of these
Calculate the [H+] in a solution that has a pH of 2.73.
2.7 M
11.3 M
1.9x10-3 M
5.4x10-12 M
none of these
Calculate the [H+] in a solution that has a pH of 8.73.
1.9x10-9 M
5.4x10-6 M
8.7x10-9 M
9.4x10-1 M
7.2x10-1 M
The pH of a solution at 25oC in which [OH-] = 3.9x10-5 M is:
4.41
3.90
9.59
4.80
none of these
In deciding which of two acids is the stronger, one must know:
the concentration of each acid solution
the pH of each acid solution
the equilibrium constant of each acid
As water is heated, its pH decreases. This means that:
the water is no longer neutral
[H+] > [OH-]
[OH-] > [H+]
None of these
At 65oC, the ion-product constant of water, Kw, is 1.20x10-13. The pH of pure water at 65oC is:
7.000
6.560
5.880
6.460
none of these
Acetic acid (HC2H3O2) is a weak acid (Ka = 1.8x10-5). Calculate the pH of a 15.1 M HC2H3O2 solution.
-1.18
3.57
1.78
1.18
12.22
Calculate the pH of the following aqueous solution:
0.35 M NaF (pKa for HF = 3.14)
5.66
2.68
8.34
11.32
none of these
Calculate the pH of the following aqueous solution:
0.39 M NH4Cl (pKb for NH3 = 4.74)
9.17
4.83
9.67
4.33
none of these
Calculate the [H+] in 1.0 M solution of Na2CO3 (for H2CO3, Ka1 = 4.3x10-7; Ka2 = 5.6x10-11).
7.5x10-6 M
6.6x10-4 M
1.3x10-2 M
7.5x10-13 M
none of these
The [H3O+] of a 0.49 M solution of NH4Cl in H2O at 25oC is (Kb for NH3 = 1.8x10-5):
2.7x10-10 M
3.0x10-3 M
1.6x10-5 M
0.49 M
none of these
Calculate the [H+] in a solution that is 0.16 M in NaF and 0.25 M in HF. (Ka = 7.2x10-4)
7.2x10-4 M
1.6 M
1.1x10-3 M
0.20 M
4.6x10-4 M
For a solution equimolar in HCN and NaCN, which statement is false?
This is an example of the common ion effect.
The [H+] is larger than it would be if only the HCN was in solution.
The [H+] is equal to the Ka.
Addition of more NaCN will shift the acid dissociation equilibrium of HCN to the left.
Addition of NaOH will increase [CN-] and decrease [HCN].
15.0 mL of 0.50 M HCl is added to a 100.-mL sample of 0.456 M HNO2 (Ka for HNO2 = 4.0x10-4). What is the equilibrium concentration of NO2- ions?
2.4x10-3 M
1.6x10-4 M
4.0x10-1 M
4.9x10-2 M
none of these
15.0 mL of 0.50 M NaOH is added to a 100.-mL sample of 0.457 M NH3 (Kb for NH3 = 1.8x10-5). What is the equilibrium concentration of NH4+ ions?
1.0x10-2 M
7.2x10-6 M
4.0x10-1 M
1.1x10-4 M
none of these
Which of the following mixtures would results in a buffered solution?
Mixing 100.0 mL of 0.100 M HCl with 100.0 mL of 0.100 M NaOH.
Mixing 100.0 mL of 0.100 M NH3 (Kb = 1.8x10-5) with 100.0 mL of NaOH.
Mixing 100.0 mL of 0.100 M HCl with 100.0 mL of 0.100 M NH3 (Kb = 1.8x10-5).
Mixing 50.0 mL of 0.100 M HCl with 100.0 mL of 0.100 M NH3 (Kb = 1.8x10-5).
At least two of these mixtures would result in a buffered solution.
Which of the following will not produce a buffered solution?
100 mL of 0.1 M Na2CO3 and 50 mL of 0.1 M HCl
100 mL of 0.1 M NaHCO3 and 25 mL of 0.2 M HCl
100 mL of 0.1 M Na2CO3 and 75 mL of 0.2 M HCl
50 mL of 0.2 M Na2CO3 and 5 mL of 1.0 M HCl
100 mL of 0.1 M Na2CO3 and 50 mL of 0.1 M NaOH
What combination of substances will give a buffered solution that has a pH of 5.05? (Assume each pair of substances is dissolved in 5.0 L of water.) (Kb for NH3 = 1.8x10-5; Kb for C5H5N = 1.7x10-9)
1.0 mole NH3 and 1.5 mole NH4Cl
1.5 mole NH3 and 1.0 mole NH4Cl
1.0 mole C5H5N and 1.5 mole C5H5NHCl
1.5 mole C5H5N and 1.0 mole C5H5NHCl
none of these
Suppose a buffer solution is made from formic acid (HCHO2) and sodium formate (NaCHO2). What is the net ionic equation for the reaction that occurs when a small amount of hydrochloric acid is added to the buffer?
H3O+(aq) + OH-(aq) → 2H2O(l)
H3O+(aq) + HCHO2(aq) → H2O(l) + H2CHO2+(aq)
HCl(aq) + OH-(aq) → H2O(l) + Cl-(aq)
HCl(aq) + CHO2-(aq) → HCHO2(aq) + Cl-(aq)
H3O+(aq) + CHO2-(aq) → HCHO2(aq) + H2O(l)
Suppose a buffer solution is made from formic acid (HCHO2) and sodium formate (NaCHO2). What is the net ionic equation for the reaction that occurs when a small amount of sodium hydroxide is added to the buffer?
H3O+(aq) + NaOH(aq) → 2H2O(l) + Na+(aq)
H3O+(aq) + OH-(aq) → H2O(l)
OH-(aq) + HCHO2(aq) → H2O(l) + CHO2-(aq)
NaOH(aq) + HCHO2(aq)→ NaCHO2(aq) + H2O(l)
Na+(aq) + HCHO2(aq) → NaH(aq) + HCO2+(aq)
A weak acid, HF, is in solution with dissolved sodium fluoride, NaF. If HCl is added, which ion will react with the extra hydrogen ions from the HCl to keep the pH from changing?
OH-
Na+
F-
Na-
none of these
Which of the following is true for a buffered solution?
The solution resists changes in its [H+].
The solution will not change pH very much even if a concentrated acid is added.
The solution will not change its pH very much even if a strong base is added.
Any H+ ions will react with a conjugate base of a weak acid already in solution.
A 100. mL sample of 0.10 M HCl is mixed with 50. mL of 0.11 M NH3. What is the resulting pH?
3.09
10.91
12.48
1.35
1.52
The following question refers to a 2.0-liter buffered solution created from 0.72 M NH3 (Kb = 1.8x10-5) and 0.26 M NH4F. What is the pH of this solution?
9.26
9.70
4.30
5.18
8.81
The following question refers to a 2.0-liter buffered solution created from 0.72 M NH3 (Kb = 1.8x10-5) and 0.26 M NH4F. When 0.10 mol of H+ is added to the solution what is the pH?
4.82
4.66
10.53
9.18
7.88
Given 100.0 mL of a buffer that is 0.50 M in HOCl and 0.77 M in NaOCl, what is the pH after 10.0 mL of 1.0 M NaOH has been added? (Ka for HOCl = 3.5x10-8)
7.68
7.74
7.46
7.12
7.79
You dissolve 1.15 grams of an unknown diprotic acid in 200.0 mL of water. This solution is just neutralized by 5.00 mL of a 1.00 M NaOH solution. What is the molar mass of the unknown acid?
230
115
28.8
460
none of these
The molar solubility of PbI2 is 1.52x10-3 M. Calculate the Ksp for PbI2.
3.51x10-9
4.62x10-6
1.40x10-8
1.52x10-3
none of these
The concentration of OH- in a saturated solution of Mg(OH)2 is 3.63x10-4 M. The Ksp of Mg(OH)2 is
6.6x10-8
4.8x10-11
1.3x10-7
3.6x10-4
2.4x10-11
The solubility of CaSO4 in pure water at 0oC is 1.14 gram(s) per liter. The value of the solubility product is
8.37x10-3
1.14x10-3
9.15x10-2
7.01x10-5
none of these
A 300.0-mL saturated solution of copper(II) periodate, Cu(IO4)2, contains 0.30 grams of dissolved salt. Determine the Ksp.
1.0x10-5
2.0x10-5
2.2x10-3
4.5x10-8
1.2x10-9
The [IO3-] in a saturated solution of Ce(IO3)3 is 5.93x10-3 M. Calculate the Ksp for Ce(IO3)3.
4.12x10-10
3.71x10-9
2.09x10-7
1.98x10-3
none of these
The correct mathematical expression for finding the molar solubility (s) of Sn(OH)2 is:
2s2 = Ksp
2s3 = Ksp
108s5 = Ksp
4s3 = Ksp
8s3 = Ksp
Find the solubility (in mol/L) of lead(II) chloride, PbCl2, at 25oC. Ksp = 1.59x10-5.
1.58x10-2
2.51x10-2
6.28x10-17
1.99x10-3
2.00x10-2
Calculate the concentration of chromate ion, CrO42-, in a saturated solution of CaCrO4 (Ksp = 7.08x10-4).
2.66x10-2 M
1.42x10-3 M
7.08x10-4 M
5.01x10-7 M
3.54x10-4 M
An unknown salt, M3Z, has a Ksp of 1.2x10-17. Calculate the solubility in mol/L of M3Z.
2.6x10-5 M
3.5x10-9 M
1.4x10-6 M
2.2x10-6 M
none of these
Which of the following compounds in the most soluble (in moles/liter)?
BaSO4
CoS
PbSO4
AgBr
BaCO3
Which of the following compounds has the lowest solubility in mol/L in water?
Al(OH)3 Ksp = 2x10-32
CdS Ksp = 1.0x10-28
PbSO4 Ksp = 1.3x10-8
Sn(OH)2 Ksp = 3x10-27
MgC2O4 Ksp = 8.6x10-5
How many moles of Fe(OH)2 [Ksp =1.8x10-15] will dissolve in 1.0 liter of water buffered at pH=10.37?
3.3x10-8
2.3x10-4
5.5x10-8
3.1x107
7.7x10-12
Given the provided Ksp values, which statement about solubility in mol/L in water is correct?
PbCrO4, Zn(OH)2, and Pb(OH)2 have equal solubilities in water.
PbCrO4 has the lowest solubility.
The solubility of MnS in water will not be pH dependent.
MnS has the highest molar solubility in water.
A saturated PbCrO4 solution will have a higher [Pb2+] than a saturated Pb(OH)2 solution.
The best explanation for the dissolution of ZnS in dilute HCl is that:
The zinc ion is amphoteric.
The sulfide-ion concentration is decreased by the formation of H2S.
The sulfide-ion concentration is decreased by oxidation to sulfur.
The zinc-ion concentration is decreased by the formation of a chloro complex.
The solublity product of ZnCl2 is less than that of ZnS.
The Ksp of Al(OH)3 is 2x10-32. At what pH will a 0.5 M Al3+ solution begin to show precipitation of Al(OH)3?
3.5
10.5
1.0
6.0
3.1
You have a solution consisting of 0.10 M Cl- and 0.10 M CrO42-. You add 0.10 M silver nitrate dropwise to this solution. Given that the Ksp for Ag2CrO4 is 9.0x10-12, and that for AgCl is 1.6x10-10, which of the following will precipitate first?
silver chloride
silver chromate
silver nitrate
cannot be determined by the information given
none of these
The following questions refer to the following system: 3.5x102 mL of 3.2 M Pb(NO3)2 and 2.0x102 mL of 0.020 M NaCl are added together. Ksp for the lead chloride is 1.6x10-5.
Determine the ion product (Q).
1.1x10-4
1.5x10-2
7.8x10-3
8.1x10-4
none of these
The following questions refer to the following system: 3.5x102 mL of 3.2 M Pb(NO3)2 and 2.0x102 mL of 0.020 M NaCl are added together. Ksp for the lead chloride is 1.6x10-5.
Will precipitation occur?
yes
no
maybe; it depends on the temperature
maybe, it depends on the limiting reagent cocentration
none of these
The following questions refer to the following system: 3.5x102 mL of 3.2 M Pb(NO3)2 and 2.0x102 mL of 0.020 M NaCl are added together. Ksp for the lead chloride is 1.6x10-5.
What is the limiting reagent in the formation of the lead chloride?
Pb2+
Cl-
(NO3)-
PbCl2
Pb(NO3)2
The following questions refer to the following system: 3.5x102 mL of 3.2 M Pb(NO3)2 and 2.0x102 mL of 0.020 M NaCl are added together. Ksp for the lead chloride is 1.6x10-5.
Determine the equilibrium concentration of the chloride ion.
3.9x10-4
8.0x10-6
2.8x10-3
6.1x10-2
none of these
For the reaction of sodium bromide with chlorine gas to form sodium chloride and bromine, the appropriate half-reactions are (ox = oxidation and re = reduction).
How many electrons are transferred in the following reaction when it is balanced in acidic solution?
SO32-(aq) + MnO4-(aq) → SO42-(aq) + Mn2+(aq)
6
2
10
5
3
The following reaction occurs in aqueous acid solution:
NO3- + I- → IO3- + NO2
In the balanced equation the coefficient of NO3- is:
2
3
4
5
6
The following reaction occurs in aqueous acid solution:
NO3- + I- → IO3- + NO2
In the balanced equation the coefficient of water is:
2
3
4
5
1
For the redox reaction 2Fe2+ + Cl2 → 2Fe3+ + 2Cl- which of the following are the correct half-reactions?
Cl2 + 2e- → 2Cl-
Cl → Cl- + e-
Cl2 → 2Cl- + 2e-
Fe2+ → Fe3+ + e-
Fe2+ + e- → Fe3+
Which energy conversion shown below takes place in a galvanic cell?
electrical to chemical
chemical to electrical
mechanical to chemical
chemical to mechanical
mechanical to electrical
Which of the following reactions is possible at the anode of a galvanic cell?
Zn → Zn2+ + 2e-
Zn2+ + 2e- → Zn
Zn2+ + Cu → Zn + Cu2+
Zn + Cu2+ → Zn2+ + Cu
two of these
Which of the following is true for the cell shown here?
Zn(s)|Zn2+(aq)||Cr3+(aq)|Cr(s)
The electrons flow from the cathode to the anode.
The electrons flow from the zinc to the chromium.
The electrons flow from the chromium to the zinc.
The chromium is oxidized.
The zinc is reduced.
Which statement is always true of the cathode in an electrochemical cell?
It is considered the "negative" electrode.
It is considered the "positive" electrode.
Reduction occurs here.
Metal is plated out here.
Negative ions flow toward the cathode.
A strip of copper is placed in a 1 M solution of copper nitrate and a strip of silver is placed in a 1 M solution of silver nitrate. The two metal strips are connected to a voltmeter by wires and a salt bridge connects the solutions. The pictured standard reduction potentials apply.
Which of the following statements is false?
Electrons flows in the external circuit from the copper electrode to the silver electrode.
The silver electrode increases in mass as the cell operates.
There is a net general movement of silver ions through the salt bridge to the copper half-cell.
Negative ions pass through the salt bridge from the silver half-cell to the copper half-cell.
Some positive copper ions pass through the salt bridge from the copper half-cell to the silver half-cell.
Which metal, Al or Ni, could reduce Zn2+ to Zn if placed in a Zn2+ solution?
Al
Ni
Both Al and Ni would work.
Neither Al nor Ni would work.
Cannot be determined.
Consider the galvanic cell shown (the contents of each half-cell are written beneath each compartment).
What is εo for this cell?
1.817 V
0.363 V
-0.363 V
4.724 V
1.316 V
Consider the galvanic cell shown (the contents of each half-cell are written beneath each compartment).
Which of the following statements about this cell is false?
This is a galvanic cell.
Electrons flow from the Pt electrode to the Cr electrode.
Reduction occurs at the Pt electrode.
The cell is not at standard conditions.
To complete the circuit, cations migrate into the left half-cell and anions migrate into the right half-cell from the salt bridge.
A cell is set up with copper and lead electrodes in contact with CuSO4(aq) and Pb(NO3)2(aq), respectively, at 25oC. The standard reduction potentials are shown.
If the Pb2+ and Cu2+ are each 1.0 M, the potential of the cell, in volts, is:
0.47 V
0.92 V
0.22 V
0.58 V
none of these
The galvanic cell described by Zn(s)|Zn2+(aq)||Cu2+(aq)|Cu(s) has a standard cell potential of 1.101 volts. Given that Zn(s) → Zn2+(aq) + 2e- has an oxidation potential of 0.764 volts, determine the reductions potential for Cu2+.
1.865 V
-1.865 V
-0.337 V
0.337 V
none of these
What is the balanced chemical equation corresponding to the following cell diagram?
Na(s)|Na+(aq)||Cu2+(aq)|Cu(s)
2Na(s) + 2Na+(aq) → Cu2+(aq) + Cu(s)
Cu(s) + 2Na+(aq) → Cu2+(aq) + 2Na(s)
2Na(s) + Cu(s) → Cu2+(aq) + 2Na+(aq)
Cu2+(aq) + Cu(s) → 2Na(s) + 2Na+(aq)
2Na(s) + Cu2+(aq) → 2Na+(aq) + Cu(s)
