Question

Hydrogen fluoride gas (HF) and sodium hydroxide (NaOH) react in a test tube. They form water and sodium fluoride (NaF). Which type of reaction occurred in the test tube?
single–replacement reaction
decomposition reaction
acid–base reaction
synthesis reaction

Answer 1

The type of reaction that occurred in the test tube is ACID BASE REACTION.
Acid base reaction is a type of chemical reaction in which an acid and a base react together to form salt and water molecules. It is also known as neutralization reaction. For the question given above, the applicable chemical reaction is as follows:
HF + NaOH = NaF + H2O
 From this chemical reaction, it can be seen that, hydrogen fluoride, which is a weak acid react with sodium hydroxide which is a strong base to produce sodium fluoride, which is a salt and a molecule of water.