Determination of Total Hardness using EDTA Titration

Play an AI-generated podcast conversation about this lesson

What is the purpose of the buffer solution added in the determination of total hardness?

To increase the concentration of EDTA
To enhance the color change of the indicator
To precipitate the calcium and magnesium ions
To adjust the pH of the solution (correct)

What is the purpose of repeating the titration for three concordant readings in the determination of total hardness?

To calculate the average volume of EDTA consumed
To determine the precision of the titration method
To ensure the accuracy of the final volume of EDTA consumed (correct)
To verify the concentration of the EDTA solution

In the determination of total hardness, what is the significance of the color change from wine red to blue?

It signifies the endpoint of the titration (correct)
It confirms the presence of EDTA in the solution
It shows the reaction between EDTA and the buffer solution
It indicates the complete removal of calcium and magnesium ions

What is the purpose of the 250 mL volumetric flask mentioned in the apparatus list for the determination of percentage purity of limestone?

To dilute the resulting solution after the reaction (C) Signup and view all the answers

In the determination of percentage purity of limestone, what is the role of the 2N HCl solution?

To react with the calcium carbonate in the limestone (D) Signup and view all the answers

What is the purpose of the methyl orange indicator used in the determination of percentage purity of limestone?

To determine the endpoint of the titration (B) Signup and view all the answers

What does the point of intersection of the two curves in the experiment represent?

Volume of NaOH solution at the equivalence point (D) Signup and view all the answers

What formula is used to determine the absolute viscosity of a fluid by Redwood viscometer?

$\text{Absolute viscosity} = -A$ (A) Signup and view all the answers

What should be avoided to prevent parallax error while taking readings in the experiment?

Touching the walls of the beaker (D) Signup and view all the answers

How can the volumes of the unknown acid solution and the amount of HCl be calculated?

By calculating N1V1 = N2V2 (A) Signup and view all the answers

What does 't' represent in the formula for kinematic viscosity by Redwood viscometer?

Time of flow in seconds for 50 ml of oil (C) Signup and view all the answers

What does 'A' represent in the formula for absolute viscosity by Redwood viscometer?

't' - time of flow in seconds for 50 ml of oil (B) Signup and view all the answers

What is the purpose of the concentrated sulfuric acid in the estimation of iron by titration with potassium permanganate?

To provide an acidic environment for the redox reaction (D) Signup and view all the answers

In the redox reaction between potassium permanganate and iron(II) ions, how many moles of iron(II) ions are required to react with one mole of permanganate ions?

5 moles (A) Signup and view all the answers

What is the role of the oxalic acid in the estimation of iron by titration with potassium permanganate?

It is used to standardize the potassium permanganate solution (A) Signup and view all the answers

In the calculation for the strength of the sodium thiosulfate solution, what does the factor '1.02' represent?

The number of moles of oxygen per mole of sodium thiosulfate (B) Signup and view all the answers

What is the purpose of using a pipette and a burette in the estimation of iron by titration with potassium permanganate?

To measure precise volumes of the iron sample and potassium permanganate solution (B) Signup and view all the answers

In the calculation for the amount of dissolved oxygen in water, what does the factor '106' represent?

The volume of water sample taken in milliliters (B) Signup and view all the answers

What should be done if the angle of rotation obtained is not exactly zero?

Include the correction in the reading (C) Signup and view all the answers

In the formula for specific rotation [∝] = 100 ∝ lC, what does 'l' represent?

Length of polarimeter tube (B) Signup and view all the answers

What is the purpose of plotting a graph between concentration of sucrose solution and angle of rotation?

To calculate the specific rotation (B) Signup and view all the answers

If the length of the polarimeter tube is 2 dm and the concentration of sucrose solution is 10 g/ml, what would be the specific rotation?

-500 deg dm–1 g–1 ml (A) Signup and view all the answers

What would be the impact on specific rotation if the concentration of sucrose solution is increased?

Specific rotation will increase (D) Signup and view all the answers

How does changing the length of the polarimeter tube affect the specific rotation?

It increases specific rotation (A) Signup and view all the answers

What is the purpose of combining the glass electrode with a reference electrode like the calomel electrode?

To measure the pH of the solution (C) Signup and view all the answers

What is the initial step in the procedure described?

Fix the temperature controller of the pH meter at 30°C (C) Signup and view all the answers

What is the purpose of adding the standard 0.5N NaOH solution to the acetic acid solution?

To neutralize the acetic acid and determine the endpoint (B) Signup and view all the answers

What is the significance of the sudden rise in pH observed during the addition of NaOH?

It indicates that the acetic acid has been completely neutralized (B) Signup and view all the answers

What is the purpose of plotting the graph of pH vs. volume of NaOH added?

To verify the accuracy of the endpoint determination (B) Signup and view all the answers

What is the significance of plotting the graph of $\frac{dpH}{dV}$ vs. volume of NaOH?

It provides a visual representation of the endpoint (A) Signup and view all the answers