उपसौर (Perihelion) और अपसौर (Aphelion) की घटना क्रमशः कब घटित होतीं हैं।
The correct statement with regard to H+2 & H−2 is
Assertion : For drying H2S, Conc. H2SO4 cannot be used.
Reason: Moist H2S is oxidized by Conc.H2SO4