Both Cr 2 O 7 2 - ( aq ) and MnO 4 - ( aq ) can be used to titrate Fe 2 + ( aq ) . If in a given titration, 24 . 50 cm 3 of 0 . 1 M Cr 2 O 7 2 - were used, then what volume of 0 . 1 M MnO 4 - solution will be consumed for the same titration in acidic medium?

Molarity of Cr 2 O 7 2 - = 0 . 1 M Molarity of MnO 4 - = 0 . 1 M Volume of Cr 2 O 7 2 - = 24 . 50 ml Volume of MnO 4 - needs to be calculated, Applying law of equivalence for titration between Fe 2 + and Cr 2 O 7 2 - Milliequivalents of Cr 2 O 7 2 - = Milliequivalents of Fe 2 + Milliequivalents = millimoles × valency factor Millimoles = Molarity × Volume in ml Millimoles of Cr 2 O 7 2 - = 0 . 1 × 24 . 5 Valency factor of Cr 2 O 7 2 - = 6 Milliequivalents of Cr 2 O 7 2 - = 0 . 1 × 24 . 5 × 6 = 14 . 7 Milliequivalents of Fe 2 + = 14 . 7 These much Fe 2 + will react with M n O 4 - Applying law of equivalence for titration between Fe 2 + and MnO 4 - Milliequivalents of MnO 4 - = Milliequivalents of Fe 2 + Milliequivalents of MnO 4 - = 14 . 7 Millimoles of MnO 4 - × Valency factor of MnO 4 - = 14 . 7 Valency Factor of MnO 4 - = 5 in acidic medium Millimoles of MnO 4 - = 14 . 7 5 = 2 . 94 Millimoles of MnO 4 - =Molarity of MnO 4 - × Volume of MnO 4 - in ml 2 . 94 = 0 . 1 × Volume of MnO 4 - Volume of MnO 4 - = 29 . 4 ml

HARD

JEE Main

IMPORTANT

Earn 100

In water, $0.5 g$ of an impure sample of oxalate was dissolved, making the solution to $100 ml$ . $10 ml$ of this required $15 ml$ of $N / 20 {KMnO}_{4}$ solution on titration. Calculate the percentage of pure oxalate in the sample.

Important Questions on Some Basic Concepts, Mole Concept and Stoichiometry

HARD

JEE Main

IMPORTANT

Chapterwise/Topicwise Daily Practice Problems (DPP) Physical Chemistry Part 1 JEE Main & Advanced>Chapter 1 - Some Basic Concepts, Mole Concept and Stoichiometry>DPP 1.6>Q 2

Both

{Cr}_{2} O_{7}^{2 -} (aq)

and

{MnO}_{4}^{-} (aq)

can be used to titrate

{Fe}^{2 +} (aq)

. If in a given titration,

24.50 {cm}^{3}

0.1 M {Cr}_{2} O_{7}^{2 -}

were used, then what volume of

0.1 M {MnO}_{4}^{-}

solution will be consumed for the same titration in acidic medium?

HARD

JEE Main

IMPORTANT

Chapterwise/Topicwise Daily Practice Problems (DPP) Physical Chemistry Part 1 JEE Main & Advanced>Chapter 1 - Some Basic Concepts, Mole Concept and Stoichiometry>DPP 1.6>Q 3

An impure sample of

{CaCO}_{3}

, that has moist clay as impurity, on heating, loses

14.5 %

of its weight of water.

5 g

of the sample shows a loss in weight by

1.507 g

. Calculate the percentage of

{CaCO}_{3}

in the sample.

HARD

JEE Main

IMPORTANT

Chapterwise/Topicwise Daily Practice Problems (DPP) Physical Chemistry Part 1 JEE Main & Advanced>Chapter 1 - Some Basic Concepts, Mole Concept and Stoichiometry>DPP 1.6>Q 4

Calculate the weight of quick lime and soda ash required to soften one million litres of hard water containing dissolved salts as shown below:

$Ca ({HCO}_{3})_{2} = 48.6 ppm; {MgCl}_{2} = 19.0 ppm; {CaSO}_{4} = 68.0 ppm; {SiO}_{2} = 15.2 ppm$ .

HARD

JEE Main

IMPORTANT

Chapterwise/Topicwise Daily Practice Problems (DPP) Physical Chemistry Part 1 JEE Main & Advanced>Chapter 1 - Some Basic Concepts, Mole Concept and Stoichiometry>DPP 1.6>Q 5

A mixture contains

{NaNO}_{3}, {AgNO}_{3}

and some impurities.

3.1 g

of the mixture was heated and the gases released were passed in pyrogallol. The weight of pyrogallol is increased by

0.208 g

. The residue left needs—for complete reaction—

25 mL

N / 10 HCl

. How much

{NaNO}_{3}

and

{AgNO}_{3}

is present in the mixture?

HARD

JEE Main

IMPORTANT

Chapterwise/Topicwise Daily Practice Problems (DPP) Physical Chemistry Part 1 JEE Main & Advanced>Chapter 1 - Some Basic Concepts, Mole Concept and Stoichiometry>DPP 1.6>Q 6

A mixture contains $20 g$ of ${NaHCO}_{3}$ , $20 g$ of ${Na}_{2} {CO}_{3}$ and $20 g$ of $NaOH$ in a litre volume vessel. $55 mL$ of the mixture is titrated with $N HCl$ . What is the titer value, if phenolphthalein is added as the first indicator?

HARD

JEE Main

IMPORTANT

Chapterwise/Topicwise Daily Practice Problems (DPP) Physical Chemistry Part 1 JEE Main & Advanced>Chapter 1 - Some Basic Concepts, Mole Concept and Stoichiometry>DPP 1.6>Q 6

A mixture contains $20 g$ of ${NaHCO}_{3}$ , $20 g$ of ${Na}_{2} {CO}_{3}$ and $20 g$ of $NaOH$ in a litre volume vessel. $55 mL$ of the mixture is titrated with the methyl orange. What is the titer value if methyl orange is added after the first endpoint?

HARD

JEE Main

IMPORTANT

Chapterwise/Topicwise Daily Practice Problems (DPP) Physical Chemistry Part 1 JEE Main & Advanced>Chapter 1 - Some Basic Concepts, Mole Concept and Stoichiometry>DPP 1.6>Q 6

HARD

JEE Main

IMPORTANT

Chapterwise/Topicwise Daily Practice Problems (DPP) Physical Chemistry Part 1 JEE Main & Advanced>Chapter 1 - Some Basic Concepts, Mole Concept and Stoichiometry>DPP 1.6>Q 7

A solution of

{Na}_{2} S_{2} O_{3}

is standardized iodometrically against

0.334 g

of pure

{KBrO}_{3}

(converted to

{Br}^{-}

) requiring

40 mL {Na}_{2} S_{2} O_{3}

solution. What is the molarity of the

{Na}_{2} S_{2} O_{3}

solution? (Molar mass of

{KBrO}_{3} = 167 g {mol}^{- 1}

)

In water, 0.5 g of an impure sample of oxalate was dissolved, making the solution to 100 ml. 10 ml of this required 15 ml of N/20 KMnO4 solution on titration. Calculate the percentage of pure oxalate in the sample.

Important Questions on Some Basic Concepts, Mole Concept and Stoichiometry

Learn and Prepare for any exam you want !

In water, $0.5 g$ of an impure sample of oxalate was dissolved, making the solution to $100 ml$ . $10 ml$ of this required $15 ml$ of $N / 20 {KMnO}_{4}$ solution on titration. Calculate the percentage of pure oxalate in the sample.