In the estimation of chloride ……………………. salt precipitate in the solutionNa2SO4NaClAgNO3AgCl

It seems like you're asking about the reaction that occurs when estimating chloride in a solution. Here's the step-by-step process:

1. The solution likely contains a salt, such as Sodium Chloride (NaCl).

2. Silver nitrate (AgNO3) is added to the solution. Silver nitrate is often used in chloride estimation because it reacts with chloride ions to form a white precipitate of Silver Chloride (AgCl).

3. The reaction that occurs is: NaCl + AgNO3 -> AgCl + NaNO3.

4. The precipitate (AgCl) is then collected and the amount of chloride in the original solution can be estimated based on the amount of precipitate.

So, the missing word in your sentence is probably "Silver Nitrate (AgNO3) is used to". The full sentence would be "In the estimation of chloride, Silver Nitrate (AgNO3) is used to precipitate the salt in the solution."