Revision Quiz PA I

Which of the following is an example of a primary standard used in titrimetric analysis?

• Potassium permanganate       

                   

• Arsenic trioxide

• Sodium hydroxide. 

•    Hydrochloric acid

Answer explanation

Arsenic trioxide is a primary standard because it has a known and stable composition, making it suitable for accurate titrimetric analysis. The other options are not primary standards.

Reagent error can be minimized by________

• Using Calibrated instruments

• Running parallel determinations     

• Running blank determinations        

• Replacing the sample

Answer explanation

Running blank determinations helps identify any background interference or reagent errors, ensuring that the results reflect only the sample's contribution. This minimizes reagent error effectively.

The pH at the equivalence point of the titration of a weak acid with a strong base

is usually ______.

• 3.5

• 7.0

• 5.5

• 8.5

Permanganate titration requires following reagent

• Sodium Hydroxide

• Sulphuric Acid

• Hydrochloric Acid

• Ethanol

__________ is a suitable indicator for the titration of a strong acid and a weak alkali.

• Methyl orange

• Phenolphthalein

• Litmus solution

• Universal indicator

Answer explanation

Methyl orange is a suitable indicator for titrating a strong acid with a weak alkali because it changes color at a pH range of 3.1 to 4.4, which is ideal for detecting the endpoint in such titrations.

The solvents which are basic in nature and used to increase the acidity of weakly acidic substances are known as

• Protogenic solvents

• Protophilic solvents

• Aprotic solvents

• None of the above

Answer explanation

Protophilic solvents are basic solvents that can accept protons, thus increasing the acidity of weakly acidic substances. This makes them the correct choice for the question.

parts per hundred

• ppm

• molarity

• percent solution

• normality

Answer explanation

'Parts per hundred' refers to a percentage, which is expressed as a 'percent solution'. Other options like ppm, molarity, and normality represent different concentration measures, making 'percent solution' the correct choice.

Which method is commonly used for the assay of Ephedrine in pharmaceutical formulations?

• Acid-base titration

• Redox titration

• Complexometric titration

• Non-aqueous titration

Answer explanation

Non-aqueous titration is commonly used for assaying Ephedrine due to its solubility in organic solvents, allowing for accurate determination in pharmaceutical formulations, unlike other titration methods.

The Ilkovic equation is used in which type of electroanalytical technique?

• Conductometry

• Potentiometry

• Polarography

• Coulometry

Answer explanation

The Ilkovic equation is specifically used in polarography, which involves measuring current as a function of voltage in an electrochemical cell. This technique is essential for analyzing the concentration of substances.

Following Titrant is used for Assay of Hydrogen Peroxide

• Sodium Hydroxide

• Silver Nitrate

• Potassium Permanganate

• EDTA

Answer explanation

Potassium Permanganate is used as a titrant for the assay of Hydrogen Peroxide due to its strong oxidizing properties, allowing for accurate determination of peroxide concentration through redox reactions.