Using `CO_(2), NH_(3),NH_(4)NO_(3)`, and `K_(2)CrO_(4)` as the only reagents, devise a qualitative analysis scheme for separating and identifying the following ions, which might all be present in the same mixture: `Ba^(2+), Ca^(2+), Mg^(2+), Na^(o+), Pb^(2+)`. Assume that each cation present is `0.10M`. State the conditions of `pH` and the reagent concentration which are required in each step.

Explanation

### Step-by-Step Solution:

1. **Initial Reaction with Ammonia (NH3) and Ammonium Nitrate (NH4NO3)**:
- **Objective**: To precipitate Lead (Pb²⁺).
- **Conditions**:
- pH should be adjusted to around 9-10 using NH3.
- The concentration of NH3 should be sufficient to maintain this pH (approximately 0.1 M).
- **Reaction**: Pb²⁺ reacts with OH⁻ to form Pb(OH)₂, which is a white precipitate.
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