In his speech, George plans to convince his audience to buy a refillable water bottle instead of disposable water bottles. What is the general purpose of George's speech?

Answer: Persuasion

Explanation: Persuasion can be define as the act of influencing someone or changing their mindset. In such case, the one persuading other must have his own mind set.

In the given case, George wants the audience to change their mindset of using plastic bottles as they are harmful for environment.

Thus, from the above we can conclude that the purpose of George behind his speech is persuasion.