What is the reaction of acid and hydroxide?

Acid and hydroxide produces a salt & Water. The system becomes neutrl.

HA + MOH = MA + H2O

Remember the general equations.

Acid + Base = Salt + Water

Acid + Alkali(hydroxide) = Salt + Water

Acid + Metal = Salt + Hydrogen

Acid + Carbonate = Salt +Water + Carbon Dioxide.

NB A Base is the oxide of a Group(I) or (II) metal. An Alkali is a soluble base. These soluble bases (alkalis) are often referred to a 'hydroxides'.