What is the concentration of a solution with a volume of .45 L that contains .9 moles of Iron (II) chloride?

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(ii) carbonate, in concentrated sulfuric acid. the sulfuric acid reacts with the copper(ii) carbonate to produce a blue solution of copper(ii) sulfate. scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction: (s) (aq) (s) (aq) suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. he adds powdered iron to a copper(ii) sulfate sample from the plant until no more copper will precipitate. he then washes, dries, and weighs the precipitate, and finds that it has a mass of .

The plant food contains nh4)3po4 what tests would you run to verify the presence of the nh4 ion and the po4 ion