Laboratory glassware is traditionally cleaned using:

Appeared in: AIIMS CRE, SNO-2024

Explanation

Potassium dichromate is a powerful oxidizing agent.
When dissolved in concentrated sulfuric acid, it forms chromic acid solution.
This solution was traditionally used to remove stubborn organic and inorganic residues from laboratory glassware, ensuring it is chemically clean for experiments.

Option A: Sodium bicarbonate is a weak base and lacks the strong oxidizing power needed to remove stubborn organic residues from glassware.
Option C: Distilled water alone cannot dissolve or remove non-polar substances like grease, oils, or baked-on organic matter.
Option D: Hydrochloric acid is effective for dissolving mineral scale or basic residues but is not the standard traditional agent for removing a broad range of organic contaminants.

Visual 1: Image - A side-by-side comparison showing a beaker with organic residue and a chemically clean beaker after being washed with chromic acid.
Visual 2: Diagram - A safety poster illustrating the necessary Personal Protective Equipment (PPE) for handling chromic acid, including gloves, goggles, and a lab coat, within a fume hood.
Visual 3: Chart - A flowchart showing the decline in the use of chromic acid and the rise of safer, modern alternatives like enzymatic detergents and base baths.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Traditional methods for cleaning laboratory glassware as background academic context rather than a clinical decision trigger.
The principle of ensuring equipment is chemically clean is fundamental in clinical laboratories to guarantee the accuracy of diagnostic tests. Contaminated glassware can lead to incorrect results, misdiagnosis, and improper patient treatment.
This question highlights the evolution of laboratory safety standards. The move away from toxic chemicals like potassium dichromate to safer alternatives reflects the modern emphasis on protecting healthcare workers and the environment.
What if the question asked for a modern, safe cleaning method? In that case, a specialized laboratory detergent or an ultrasonic bath would be a more appropriate answer, as chromic acid is now largely obsolete due to safety concerns.

How to Approach the Question

Identify the core of the question: it asks for a 'traditional' cleaning agent for lab glassware.
Analyze the options based on their chemical properties and common laboratory uses.
Sodium Bicarbonate is a weak base, mainly for neutralization.
Distilled water is a rinsing agent, not a primary cleaner for organic material.
Hydrochloric acid is for specific mineral deposits.
Potassium dichromate is a strong oxidizing agent, which is characteristic of a heavy-duty cleaning solution capable of removing stubborn organic residues.

Concept Tested & Keywords

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