From the list given below, select the word (s) required complete the blanks (i) to (v) in the following passage :
Note : words chosen from the list are to be used only once. Write only the answers. Do not copy the passage
[reddish brown, ammonium, nitrogen dioxide, hydroxyl, dirty green, ammonia, acidic, alkaline]
Nitrogen and hydrogen combine in the presence of a catalyst to give (i) ________ gas. When the above mentioned gas is passed through water it forms a solution which will be (ii) ______ in nature and the solution contains (iii) ______ ions and (iv) _______ions. The above solution when added to iron (II) sulphate solution gives a (v) _________coloured precipitate of iron (II) hydroxide.