Sulphuric acid is made up of two hydrogen atoms, one sulfur atom, and four oxygen atoms. It has the chemical formula H2SO4 and can be used as a bleaching agent and disinfectant. Nitric acid is a highly toxic and corrosive mineral acid that is colorless when pure and also known as aqua fortis or spirit of nitre. Citric acid is a natural preservative that is used to add an acidic or sour taste to foods and drinks, and has the formula C6H8O7.