59. With conc. H2SO4 Tartaric acid decomposes into..
Answers
Answer:
It depends on whether a particular acid has strong oxidising or reducing property.
Concentrated nitric and sulphuric acids are powerful oxidising agents and so readily react with hydobromic and hydroiodic acids, which are strong reducing agents. The reactions are faster at elevated temperatures.
2HNO3 + 2HBr = 2NO2 + Br2 + 2H2O
H2SO4 + 2HI = SO2 + I2 + 2H2O
The hydrogen halides are oxidised to respective free halogens, and the oxo-acids are in turn reduced to lower oxides such as NO2 and SO2. Thus, such reactions are typical redox reactions.
Even in aqua regia (1:3 mixure of conc.HNO3 and conc.HCl), hydochloric acid is oxidised to free chlorine by concentrated nitric acid. HCl acid is a mild reducing agent.
HNO3 + 3HCl = NOCl + Cl2 + 2H2O
Nitrosyl chloride (NOCl) further decomposes to NO and nascent chlorine.
In concentrated sulphuric acid relatively weaker acids like nitric acid and acetic acid act like a base (proton acceptor).
H2SO4 + HNO3 = HSO4(-) + NO2(+) + H2O
But such interactions are not chemical reactions in the real sense of the term.