graduated cylinders are not as precisely calibrated as are burets or volumetric pipets. briefly explain why it is acceptable to measure KI and HCl solutions in the titration with graduated cylinders rather than with pipets or burets.
I agree with what you've said but without knowing the particulars of the experiment I can't help you. Are you titrating I2 with thiosulfate? If so you measured the KIO3 precisely. The KI is an excess reagent and the amount of the excess is not that important and the HCl is just to make it acid; the precise acidity is not required. Clarify the post if I haven't guessed right.
Graduated cylinders are widely used in general laboratory settings for approximate measurements, as they provide a rough estimation of volume, but they are not as precise as burets or volumetric pipets. However, for certain applications like titrations with KI and HCl solutions, it is acceptable to use graduated cylinders instead of pipets or burets.
The reason behind this acceptability lies in the nature of the titration itself. In a typical titration, a known volume of a solution (titrant) with a known concentration is added to react with an unknown volume of another solution (analyte) until a chemical reaction reaches its equivalence point. This point indicates the precise stoichiometric equivalence of the two reactants.
In the case of KI and HCl solutions, the reaction between them is relatively fast and produces a clear visual indication of the equivalence point. This indication is usually a color change caused by the formation of a precipitate or the use of an indicator dye. Since the reaction is rapid and the equivalence point can be easily identified, the precise measurement of volumes becomes less crucial.
Therefore, for titrations with KI and HCl solutions, the goal is often to reach the equivalence point rather than obtaining highly accurate volume measurements. Graduated cylinders, while not as precise as burets or pipets, can still provide reasonably accurate estimations of volume, allowing for successful titrations. However, it is important to note that if the titration requires high precision or has a lower tolerance for error, using more precise volumetric equipment like burets or pipets would be recommended.
Graduated cylinders are not as precisely calibrated as burets or volumetric pipets due to their larger graduations and wider tolerance for error. However, for measuring KI and HCl solutions in titration, using graduated cylinders is acceptable for a few reasons:
1. Relative Comparisons: In titration, the focus is primarily on the volume of solution added, rather than its absolute accuracy. Graduated cylinders provide sufficient precision for making relative comparisons and determining the endpoint of the titration.
2. Appropriate Precision: The concentrations of KI and HCl solutions used in titrations are typically relatively high and not extremely sensitive to small variations in volume. The concentrations are often determined through standardization, where accurate volume measurement is less critical.
3. Time and Convenience: Graduated cylinders are quick and easy to use, enabling efficient measurements in a titration process. This is especially useful when multiple titrations need to be performed within a short timeframe.
4. Cost Considerations: Graduated cylinders are more cost-effective compared to burets or calibrated pipets, making them a practical choice in situations where high levels of accuracy are not essential.
That being said, it is important to note that using precise instruments like burets or volumetric pipets would yield more accurate and reliable results, especially in cases where highly accurate measurements are required or when working with low-concentration solutions.