Hydrogen fluoride (HF) can form when which of the following occurs?

Hydrogen fluoride (HF) can form when which of the following occurs?

• A. Fluorine goes through thermal decomposition
• B. Hydrogen reacts with oxygen
• C. Water is boiled
• D. Chlorine is introduced

Answer: (A)

HF forms when hydrogen meets fluorine to create the HF bond; fluorine is extremely reactive and readily bonds with hydrogen. The only scenario among the options that provides fluorine in a way that can react with hydrogen is when a fluorine-containing substance decomposes with heat to release fluorine, which then bonds with hydrogen to give HF. The other choices involve reactions that don’t produce fluorine: hydrogen reacting with oxygen makes water, boiling water is just a phase change, and introducing chlorine would form hydrogen chloride under typical conditions. So, releasing fluorine by thermal decomposition is the condition that leads to HF formation.

HF forms when hydrogen meets fluorine to create the HF bond; fluorine is extremely reactive and readily bonds with hydrogen. The only scenario among the options that provides fluorine in a way that can react with hydrogen is when a fluorine-containing substance decomposes with heat to release fluorine, which then bonds with hydrogen to give HF. The other choices involve reactions that don’t produce fluorine: hydrogen reacting with oxygen makes water, boiling water is just a phase change, and introducing chlorine would form hydrogen chloride under typical conditions. So, releasing fluorine by thermal decomposition is the condition that leads to HF formation.