Which combination cannot be used for thepreparation of hydrogen gas in the laboratory?
I.Zn/conc.H2SO4(Impure Zinc is used)
II.Zn/dil.HNO3 (Impure Zinc is used)
III.Zn/dil.H2SO4 (Very highly pure Zn is used)
Question 11 Which of the following metals exist in their native state in nature? (i) Cu (ii) Au (iii) Zn (iv) Ag (a) (i) and (ii) (b) (ii) and (iii) (c) (ii) and (iv) (d) (iii) and (iv)