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

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.