Test Preparation on s-block Elements-I-Chemistry Test Series For NEET-2020
1.
Which one of the following substances is used in the laboratory for a fast drying of neutral gases
Anhydrous CaCl2 is used for fast drying of neutral gases.
2.
3.
Which of the following statements about hydrogen is incorrect
(a) Hydrogen has three isotopes of which tritium is the most common (b) Hydrogen never acts as cation in ionic salts (c) Hydronium ion, H3O+ exists freely in solution (d) Dihydrogen acts as a reducing agent
4.
5.
Hydrogen can be prepared by the action of dil. H2SO4 on
Hydrogen cannot be prepared by the action of dil. H2SO4 on copper or mercury as these two metals can not displace hydrogen from acids. Action of dil. H2SO4 on Pb stops after sometime due to the formation of insoluble PbSO4 . Only iron reacts rapidly with dil. H2SO4 to give H2 .