0.00012% `MgSO_(4)` and `0.000111% CaCl_(2)` is present in water. What is the measured hardness of water and millimoles of washing soda required to purigy water 1000 L water ?

Explanation

To solve the problem of determining the hardness of water and the millimoles of washing soda required to purify 1000 liters of water containing 0.00012% MgSO₄ and 0.000111% CaCl₂, we will follow these steps:

### Step 1: Calculate the mass of MgSO₄ and CaCl₂ in 100 grams of water.
Given:
- 0.00012% MgSO₄ means 0.00012 grams of MgSO₄ in 100 grams of water.
- 0.000111% CaCl₂ means 0.000111 grams of CaCl₂ in 100 grams of water.

### Step 2: Calculate the number of moles of MgSO₄.
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