Question: what is the most powerfull explosion done in a lab so far?

Jesus Calvo-Castro answered on 8 Nov 2015:

Reactions in labs are quite controlled, which means that they usually involved very small amounts or concentrations. Elements of the first group such as sodium react violently with water (this is called a very exothermic reaction, gives away a lot of energy). I myself use an explosive reaction regularly to clean glassware. We call it bombing the glassware and it uses fume nitric acid (very very concentrated) and ethanol.