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What role does a reagent play in a chemical analysis?
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chemical analysis
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In chemical analysis, a reagent is a substance utilized for its chemical or biological activity to detect, measure, or examine a component within a sample, known as the analyte.12
The role of a reagent varies depending on the analytical method:
- Qualitative Analysis: Reagents are added to an analyte to trigger specific chemical reactions. By observing the formation of distinctive products—such as a precipitate, a gas, or a color change—analysts can deduce the identity of the substance being tested.3
- Quantitative Analysis: Reagents are used to determine the amount or concentration of an analyte. In volumetric analysis, a reagent of known concentration, called a titrant, is added until the reaction is complete, allowing for precise calculations based on the volume used. In gravimetric analysis, a reagent is added to form a solid precipitate that can be filtered, dried, and weighed to calculate the initial amount of the analyte.2
- Instrumental Analysis: Reagents may be used in conjunction with instruments to characterize reactions or facilitate the measurement of specific chemical properties.2