When reacted with metals, acids liberate?

Bases change the orange colour of the methyl orange solution to?

Acids are sour to taste they turn litmus

The pH of pure water is 

Combination of H⁺ and OH^- ions is called 

The pH was introduced by

Neutral solution has pH  

The theory of ionisation of acids and bases were proposed by

Bases are substances, they produce

If an acid is completely ionized, it is called a