In volumetric analysis, for which type of analysis is it necessary to collect timed specimens?

• A. Preparation of calibration curves
• B. Kinetic studies of reaction rates
• C. Gravimetric determination of solids
• D. Standardization of titrant solutions

Answer: (B)

Verified step by step guidance

1. Understand the context of volumetric analysis: Volumetric analysis involves measuring the volume of a solution to determine the concentration of a substance. Timed specimens are collected when the reaction rate or time-dependent changes are critical to the analysis.
2. Review the options provided: The problem lists four types of analyses: (1) Preparation of calibration curves, (2) Kinetic studies of reaction rates, (3) Gravimetric determination of solids, and (4) Standardization of titrant solutions.
3. Analyze each option: (1) Preparation of calibration curves does not require timed specimens because it involves creating a relationship between concentration and instrument response. (2) Kinetic studies of reaction rates require timed specimens because reaction rates depend on time and must be measured at specific intervals. (3) Gravimetric determination of solids involves weighing solids and does not depend on time. (4) Standardization of titrant solutions involves determining the concentration of a titrant and does not require timed specimens.
4. Conclude that the correct type of analysis requiring timed specimens is 'Kinetic studies of reaction rates,' as this involves monitoring how the concentration of reactants or products changes over time.
5. Understand the importance of timed specimens in kinetic studies: Timed specimens allow for the calculation of reaction rates and the determination of rate laws, which are essential for understanding the mechanism of a chemical reaction.