Identify the unknown species and complete the following
(i)`(A)+BaCl_(2) to` White precipitate
(ii)`NaOH+(B)to NH_(3)` gas
(iii)`( C)+MnO_(2)+H_(2)SO_(4) to` Violet vapours
(iv)`(D)+K_(2)Cr_(2)O_(7)+H_(2)SO_(4) to` Green coloured solution
(vi)`undersetunderset("solid")("Colourless")(E)overset("Heat")to` Yellow copound

Explanation

To identify the unknown species A, B, C, D, and E, we will analyze each reaction step by step.

### Step-by-Step Solution:

1. **Identifying A:**
- The reaction is `(A) + BaCl2 → White precipitate`.
- A white precipitate with BaCl2 suggests the formation of BaSO4, which is a common white precipitate.
- Therefore, A must be a sulfate.
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