REDOX TITRATIONS PERMANGANOMETRY

Potassium Permanganate (KMnO4)

Strong oxidizing agent

Potassium Permanganate (KMnO4)

with an intense violet color

acidic

Potassium Permanganate (KMnO4): As a volumetric solution, it is a self-indicating titrant in _ media

self-indicating

Potassium Permanganate (KMnO4): As a volumetric solution, it is a _ titrant in acidic media

Potassium Permanganate (KMnO4)

As a volumetric solution, it is a self-indicating titrant in acidic media

re-standardized

Potassium Permanganate (KMnO4): It is stable when proper precautions are observed in its preparation and

preservation. Otherwise, it must be _ prior to use.

Potassium Permanganate (KMnO4)

It is stable when proper precautions are observed in its preparation and

preservation. Otherwise, it must be re-standardized prior to use.

Purple

Permanangate Color

MnO4-

Permanangate Sample/Form

+7

Permanangate Oxidation state

Deep green

Manganate Color

MnO42-

Manganate Sample/Form

+6

Manganate Oxidation state

Dark brown

Manganese dioxide Color

MnO2

Manganese dioxide Sample/Form

+4

Manganese dioxide Oxidation state

Colorless or very pale pink

Manganese chloride Color

Mn2+ (MnCl2)

Manganese chloride Sample/Form

+2 (most stable)

Manganese chloride Oxidation state

Condy's crystal, permanganate of potash, chameleon mineral, and potassium manganate(VII)

Potassium Permanganate (KMnO4) other terms 4

Potassium Permanganate (KMnO4)

does not require indicator

Potassium Permanganate (KMnO4)

self-indicating

Potassium Permanganate (KMnO4)

obvious color change depending on oxidation state

Potassium Permanganate (KMnO4)

may require a permit to get it

Potassium Permanganate (KMnO4)

used for explosive substances

manganese(II) ions (Mn²⁺).

In strongly acidic solutions, manganate (VII) is reduced to _

intense purple

MnO4- + 8H+ + 5e- → Mn2+ +4H2O

manganate color

colorless/very pale pink

MnO4- + 8H+ + 5e- → Mn2+ +4H2O

manganese ions color

brown solid, MnO2

in neutral/alkaline solns, the product is the _

green manganate

in strongly alkaline soln (2M NaOH) __ is produced

analytical balance

in analytical measurements, ____ is always used

KMnO4

it is not a primary standard

distilled

what kind of water must be used

Boiling

it is necessary for the freshly prepared of KMnO4 to prevent decomposition to. MnO2

KMnO4

allow to stand for 2 days (or 3)

Filtration

removes undissolved KMnO4 and other impurities and decomposition

Label and Protect

_ and ? the soln from light

arsenic (III) oxide (As2O3)

sodium oxalate (Na2C2O4)

Standardize KMnO4 using either primary standards (2)

excess KMnO4

is usually taken since some crystals of KMnO4 will be remained undissolved

KMnO4

primary standard/analyte

down

when not dried, weight will go _

110 degree Celsius

dry using oven at __

dried to constant wt (usp)

drying shall be continued until 2 consecutive weighings, the 2nd of which taken after an additional drying period appropriate to the nature and quantity of residue (substance) do not differ by more than 0.50mg per g of subs. taken

sulfuric acid

most suitable acid, no action upon permanganate

acidic

titration condition must be _ for rxn to proceed forward →

60-70 degree celcius

heated to around _ to hasten rxn of KMnO4- and oxalate

KMnO4- and oxalate

heated to around 60-70 degree celcius to hasten rxn of _ 2

chemical rxn

increase _ weight between KMnO4 and oxalate

Direct Titration

Potassium Permanganate (KMnO4) Type of titration:

Redox reaction

Potassium Permanganate (KMnO4) Type:

Na2C2O4 (analyte, 1o standard)

Potassium Permanganate (KMnO4) Reducing agent

KMnO4 (titrant, volumetric solution, 2o standard)

Potassium Permanganate (KMnO4) Oxidizing agent

H2SO4

Potassium Permanganate (KMnO4) Acidifying agent

8H2SO4 + 5Na2C2O4 + 2KMnO4 → 2MnSO4 + 5Na2SO4 + K2SO4 + 10CO2 + 8H2O

Potassium Permanganate (KMnO4) Chemical reaction:

2 (because in the half-equation reaction of oxalate, it loses 2e-.

Potassium Permanganate (KMnO4) Factor (of analyte):

KMnO4

The standardization of _ using As2O3 is done in an alkaline medium. It is solubilized first with NaOH or KOH before reacting with KMnO4.

As2O3

The standardization of KMnO4 using _ is done in an alkaline medium. It is solubilized first with NaOH or KOH before reacting with KMnO4.

alkaline

The standardization of KMnO4 using As2O3 is done in an _ medium. It is solubilized first with NaOH or KOH before reacting with KMnO4.

NaOH or KOH

The standardization of KMnO4 using As2O3 is done in an alkaline medium. It is solubilized first with _ or ? before reacting with KMnO4.

KMnO4

The standardization of KMnO4 using As2O3 is done in an alkaline medium. It is solubilized first with NaOH or KOH before reacting with _.

redox

What is the type of chemical reaction between KMnO4 and

Na2C2O4?

direct

What is the type of titration to be employed?

sodium oxalate & arsenict rioxide

What is the primary standard used?

none

What is the indicator used?

colorless to endpink

Describe the color transition of endpoint.