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A chemistry student trying to detect the...

A chemistry student trying to detect the metallic ion in a salt, makes a paste on a clean platinum wire loop of the salt with concentrated HCl. When he takes a small amount of this paste and keeps it in a non-luminous Bunsen flame, the colour of the flame changes to grassy green.He should, therefore, conclude that the metal is

A

Barium

B

Calcium

C

Potassium

D

Strontium

Text Solution

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The correct Answer is:
To determine the metallic ion in the salt based on the flame test described, we can follow these steps: ### Step-by-Step Solution: 1. **Understanding the Flame Test**: The flame test is a qualitative analysis technique used to identify the presence of certain metal ions based on the color they emit when heated in a flame. 2. **Preparation of the Sample**: The student prepares a paste of the salt with concentrated hydrochloric acid (HCl) on a clean platinum wire loop. This step ensures that any contaminants are removed, allowing for an accurate test. 3. **Conducting the Flame Test**: The platinum wire loop, now coated with the paste, is introduced into a non-luminous Bunsen flame. The flame should be non-luminous to avoid interference from soot and other contaminants. 4. **Observation of Flame Color**: The student observes that the color of the flame changes to grassy green. This observation is crucial as different metal ions produce characteristic flame colors. 5. **Identifying the Metal Ion**: Based on known results from flame tests: - Barium produces a grassy green flame. - Calcium produces an orange-red flame. - Potassium produces a pink flame. - Strontium produces a red flame. 6. **Conclusion**: Since the observed flame color is grassy green, the student concludes that the metallic ion in the salt is **Barium (A)**. ### Final Answer: The metal is **Barium (A)**. ---
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