Question

why do onions become odourless when soaked in vinegar? ???

Answer 1

1.onion contains many chemical which brings tears in your eye as u all know. vinegar contain many chemical which kills germs and chemical present inonion which makes it odourless.
2.onion contains basic nature and vinegar contains acidic natural
acid +basce=neutral

Answer 2

because onion show basic nature and vinager show acidic nature . When onion is soaked in vinegar neutralization reaction occur which nullify then odour of onion.