The composition of aqua-regia is x parts of conc. HCl and y parts of conc. `HNO_(3)`. The value of x + y is

Explanation

To solve the question regarding the composition of aqua regia, we need to determine the values of x and y, where x represents the parts of concentrated hydrochloric acid (HCl) and y represents the parts of concentrated nitric acid (HNO3).

### Step-by-Step Solution:

1. **Understanding Aqua Regia Composition**:
Aqua regia is a mixture of hydrochloric acid (HCl) and nitric acid (HNO3) in a specific ratio. The commonly accepted ratio is 3 parts HCl to 1 part HNO3.

2. **Identifying x and y**:
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