A sample of hard water contains 1 mg `CaCl_2` and 1 mg `MgCl_2` per litre. Calculate the hardness of water in terms of `CaCO_3` present in per `10^(6)` parts of water.
(a). 2.5 ppm
(b). 1.95 ppm
(c). 2.15 ppm
(d). 195 ppm

Explanation

To calculate the hardness of water in terms of `CaCO3` present in per `10^6` parts of water, we will follow these steps:

### Step 1: Understand the Composition of Hard Water
The sample of hard water contains:
- 1 mg of `CaCl2` per liter
- 1 mg of `MgCl2` per liter

### Step 2: Calculate the Equivalent `CaCO3` from `MgCl2`
...