Fill in the blanks with suitable words :
An acid is a compound which when dissolved in water forms hydronium ions as the only ________ ions.
A base is a compound which is soluble in water contains ________ ions. A base reacts with an acid to form a ________ and water only. This type of reaction is known as ________
An element A reacts with water to form a compound B which is used in whitewashing. The compound B on heating forms an oxide C which on treatment with water gives back B. Identify A, B, and C and give the reactions involved.