[header] How to demonstrate that oxides formed by nonmetals are acidic [title] Take a deflagrating spoon. [step] You can get such a spoon in a chemistry lab [title] Put some sulphur powder (a non-metal) in a jar. [step] They are yellow in colour. 
[title] Take 1 spoon of sulphur powder in a deflagrating spoon. [title] Heat the deflagrating spoon using a minus heater.