Question

In: Chemistry

Please show how to find moles of KMnO4 added, moles of Fe3+, mass of Fe3+, and...

Please show how to find moles of KMnO4 added, moles of Fe3+, mass of Fe3+, and mass percent of Fe3+

For my standardization of KMnO4 the average molarity was 2.11x10-2M I'm not sure if that's needed to solve

a) Balanced net ionic equation for the redox reaction of Fe2+and MnO4-: 5Fe+2+ MnO4-2+ 8H+Þ 5Fe+3+Mn+2+ 4H2O

b) Data:

Run

Mass of Green Salt (g)

Vol. KMnO4 (mLs)

– Vol. blank (mLs)

Difference in vol. (mLs)

Moles KMnO4 added

Moles Fe3+

Mass of Fe3+ (g)

Mass % Fe3+

1

.1168g

4mL

.2mL

3.8mL

2

.1038g

3.1mL

.2mL

2.9mL

Average mass % Fe3+

Solutions

Expert Solution

b) Start with the balanced chemical equation.

5 Fe2+ + MnO4- + 8 H+ -----> 5 Fe3+ + Mn2+ + 4 H2O

As per the balanced chemical equation,

5 moles Fe3+ = 1 mole MnO4-

Fill up the table as given.

Run

1

2

a) Mass of green salt (g)

0.1168

0.1038

b) Vol. of KMnO4 (mL)

4.0

3.1

c) Vol. of blank (mL)

0.2

0.2

d) Difference in vol (mL) (b – c)

3.8

2.9

e) Moles KMnO4 added = (d/1000)*(2.11*10-2 M) (check sample calculation I)

8.018*10-5

6.119*10-5

f) Moles Fe3+ (check sample calculation II)

4.009*10-4

2.4476*10-4

g) Mass Fe3+ (g) (check sample calculation III)

0.02239

0.01367

h) Mass % Fe3+ (check sample calculation IV)

19.1695

12.9206

i) Average mass % Fe3+ (check sample calculation V)

16.04505 ≈ 16.045

Sample calculation I:

Moles of KMnO4 taken = (vol. of KMnO4 in L)*(concentration of KMnO4 in mol/L) = (3.8 mL)*(1 L/1000 mL)*(2.11*10-2 mol/L) = 8.018*10-5 mol.

Sample calculation II:

As per stoichiometric equation above, 1 mole MnO4- = 5 moles Fe3+.

Therefore, 8.018*10-5 mole KMnO4 = (8.018*10-5 mole MnO4-)*(5 moles Fe3+/1 mole MnO4-) = 4.009*10-4 mole.

Sample calculation III:

Molar mass of Fe = 55.85 g/mol.

Therefore, mass of Fe3+ = (4.009*10-4 mole)*(55.85 g/mol) = 0.02239 g

Sample calculation IV:

Mass% Fe3+ = (mass of Fe3+/mass of sample)*100 = (0.02239 g/0.1168 g)*100 = 19.1695

Sample calculation V:

Average mass% Fe3+ = (19.1695 + 12.9206)/2 = 16.04505


Related Solutions

Please show how to find moles of KMnO4 added, moles of Fe3+, mass of Fe3+, and...
Please show how to find moles of KMnO4 added, moles of Fe3+, mass of Fe3+, and mass percent of Fe3+ For my standardization of KMnO4 the average molarity was 2.11x10-2M I'm not sure if that's needed to solve a) Balanced net ionic equation for the redox reaction of Fe2+and MnO4-: 5Fe+2+ MnO4-2+ 8H+Þ 5Fe+3+Mn+2+ 4H2O b) Data: Run Mass of Green Salt (g) Vol. KMnO4 (mLs) – Vol. blank (mLs) Difference in vol. (mLs) Moles KMnO4 added Moles Fe3+ Mass...
What is the mass percent of ethanol (CH33​CH22​OH) if 0.0786 moles of ethanol is added to...
What is the mass percent of ethanol (CH33​CH22​OH) if 0.0786 moles of ethanol is added to 0.279 kg of water?
Write a balanced equation for the oxidation of methanol with KMnO4 in acidic solution; show how...
Write a balanced equation for the oxidation of methanol with KMnO4 in acidic solution; show how you balanced the reaction using half-reactions.
1a)  From the volume of titrant added, calculate the moles of vitamin C for each titration. Show...
1a)  From the volume of titrant added, calculate the moles of vitamin C for each titration. Show a sample calculation for trial 1, and then just state the final results for the calculation of trials 2 and 3. Use 5 digits in all intermediate values and report the final value to the appropriate number of significant figures. Trial 1 Trial 2 Trial 3 b) From the results of question 1, calculate the average value for the number of moles of vitamin...
How many moles of sodium hydroxide would have to be added to 250 mL of a...
How many moles of sodium hydroxide would have to be added to 250 mL of a 0.357 M hypochlorous acid solution, in order to prepare a buffer with a pH of 7.640?
How many moles of sodium hydroxide would have to be added to 250 mL of a...
How many moles of sodium hydroxide would have to be added to 250 mL of a 0.436 M acetic acid solution, in order to prepare a buffer with a pH of 4.630? moles
If 500 mg of Fe3+ and 50 mg of OH- are added to 1L of pure...
If 500 mg of Fe3+ and 50 mg of OH- are added to 1L of pure water, what will be the final equilibrium concentration of Fe3+ and OH-. Assume water does not dissociate. Fe(OH)3 => Fe3++3OH-, pKs =38.57, MWFe = 55.85 g/mol, MWOH = 17.01 g/mol
How many moles of potassium chloride must be added to the solution to completely precipitate 1.18g...
How many moles of potassium chloride must be added to the solution to completely precipitate 1.18g dissolved Ag?
How many moles of KF should be added to 0.50 L of a 0.10 M HF...
How many moles of KF should be added to 0.50 L of a 0.10 M HF solution to prepare a buffer with a pH of 2.84?
Potassium permanganate (KMnO4) is sometimes added to water as it enters a drinking water treatment plant...
Potassium permanganate (KMnO4) is sometimes added to water as it enters a drinking water treatment plant to assist in the removal of Fe2+ and Mn2+ ions. The KMnO4 oxidizes those cations by acquiring electrons according to the following reaction: KMnO4 + 4H+ + 3e ↔ K+ + MnO2(s) + 2H2O a) What is the (electron) equivalent weight of Mn, based on this reaction? b) Calculate the mass (g) of KMnO4 in 2 L of a 0.15 M KMnO4 solution. c)...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT