What is Tollen's reagent? Write one usefulness of this reagent.

Explanation

**Step-by-Step Solution:**

1. **Definition of Tollen's Reagent:**
Tollen's reagent is a chemical reagent used in organic chemistry. It is prepared by dissolving silver nitrate (AgNO3) in ammonia (NH4OH). The resulting solution is a colorless liquid that contains the complex ion [Ag(NH3)2]+, which is responsible for its reactivity.

2. **Chemical Composition:**
The chemical formula for Tollen's reagent can be represented as:
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