We did an experiment using dilute hydrochloric acid & sodium thiosulphate and I asked why we didn't need to wear gloves. I was told it was because the HCl was very diluted and therefore not harmful if you got it on your hands.
The concentration of HCl(aq) was 2M (ie, I think, 73g of HCl per 1 litre of water?). I'm curious to know - what concentration of HCl would be harmful on the skin? Can anyone tell me please?