Enter a complete ionic equation to show the reaction of aqueous Hg2(NO3)2 with aqueous sodium chloride to form solid Hg2Cl2 and aqueous sodium nitrate. Express your answer as a complete ionic equation. Identify all of the phases in your answer.

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.  

A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.  

The balanced chemical equation is:

The complete ionic equation will be :

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.