What type of reaction does the following chemical equation describe?
#HCl + NaOH -> NaCl + H_2O#
It is a double replacement because the reaction starts with two compounds and ends with two compounds where the positive and negative ions have changed places.
The positive hydrogen ion on the Chlorine has been replaced by a positive sodium ion on the Chlorine. While the Sodium ion on the hydroxide has been replaced by the Hydrogen ion. This double replacement makes this a double replacement reaction.
The reaction is also a neutralization because
After the reactions the products are a salt and water. The acid and the base have neutralized each other.