Rohan says you should never touch any acid, because all acids burn you

Why

Rohan has probably heard about strong acids in a lab, which really can burn skin, and has stretched that to 'all acids'. But 'acid' covers a huge range of strengths. Many acids are weak and completely harmless in the amounts we meet them — the citric acid that makes a lemon or an orange sour, the acetic acid in the vinegar on chaat, the lactic acid in curd and yoghurt, the carbonic acid in a fizzy drink. People eat and drink these every single day. Test it: a lemon is full of acid, yet squeezing one and getting the juice on your hands does nothing worse than sting a cut. His sister is right: many acids are weak and safe in everyday amounts — some strong acids are dangerous, but 'acid' by itself does not mean harmful.