What is Blue vitriol chemically known

To kill two birds with one stone 

Find the word with the appropriate similar meaning of the word in Italic from the options given:

The team worked on the project with zeal .

In the following question select the answer pair that expresses a relationship most similar to that expressed in the capitalised pair.

Blend

His speech was articulate and well-delivered.

Heart : Cardiology :: Insects : ?

Deadlock 

Select the most appropriate synonym of the given word.

Diligent

Puerile

Select the wrongly spelt word.