A lab reagent is a substance used to cause a chemical reaction, detect another substance, measure a substance, or produce a new substance in a laboratory setting.
Essentially, reagents are the working components in many chemical experiments and analyses. They are the ingredients that drive the processes researchers and technicians use daily.
Here's a more detailed breakdown:
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Purpose: Reagents serve various crucial roles in the lab:
- Reactants: They can act as reactants in a chemical reaction, combining with other substances to form new products.
- Detectors: Reagents are employed to identify or confirm the presence of specific substances. An example is using iodine to detect the presence of starch. The iodine reagent will turn dark blue or black in the presence of starch.
- Titrants: Reagents can be used in titrations to determine the concentration of an unknown solution.
- Standardization: They are used to standardize other solutions by carefully reacting with them.
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Examples: Common lab reagents include:
- Acids (e.g., hydrochloric acid, sulfuric acid)
- Bases (e.g., sodium hydroxide, potassium hydroxide)
- Solvents (e.g., water, ethanol, acetone)
- Indicators (e.g., phenolphthalein, litmus)
- Salts (e.g., sodium chloride, potassium chloride)
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Quality: Reagents are often manufactured to specific purity standards. "ACS grade" or "reagent grade" indicates a high level of purity suitable for many analytical applications. Impurities in reagents can interfere with experiments, leading to inaccurate results.
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Storage and Handling: Proper storage and handling of reagents are critical for safety and to maintain their integrity. This often involves storing them in appropriate containers, at specific temperatures, and away from incompatible substances. Always consult the Safety Data Sheet (SDS) for specific instructions for each reagent.
In summary, a lab reagent is a vital substance employed in laboratory tests to facilitate chemical reactions, detections, measurements, and substance creation. The appropriate selection, handling, and storage of reagents are crucial to the reliability and accuracy of experimental results.