Why Kaysons ?

Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

Live Doubt Clearing Session

Ask your doubts live everyday Join our live doubt clearing session conducted by our experts.

National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.


Hydrogen and S block

  • 1
  • 2
  • 3
  • 4


What is the function of potassium nitrate in gun powder?


An aqueous solution of salt ‘R’ when treated with dil HCl, a colourless gas is given out. The gas so evolved when passed through acidified KMnO4 decolourises KMnO4 solution. The salt ‘R’ is


In Down’s cell (for production of sodium), graphite anode is used because


Which can dissolve ?

Q. A solution of sodium metal in liquid ammonia is strongly reducing due to the presence of?

Presence of solvated electrons makes solution of alkali metal in liquid ammonia makes them strongly reducing agent.

Q. what do the variables x and y mean in the reaction of alkali metals,with (x+y)NH3? The reaction is M + (x+y)NH3 ---------> [M(NH3)x]+ + [e(NH3)y]?

X is the number of NH3 present in the coordination compound y is number of NH3 present outside coordination

Q. While going down the group the solubility of carbonates of Alkali metals increase whereas in Alkaline Earth Metals it decreases down the group? Give reason. I Was thinking in terms of change in hydration energy (directly proportional to solubility) and lattice energy (inversely proportional to solubility) but I can't understand why this irregularity occur?

The size of anions being much larger as compared to cations, the lattice enthalpy will remain almost constant within a particular group. Since the hydration enthalpy decreases down the group, solubility will decreases as found for alkaline earth metal carbonates and sulphates.

Q. The alkali metals form salt-like hydrides by the direct synthesis at elevated temperature. The thermal stability of these hydrides decreases in which order?

As the size of alkali metal ion increases, lattice energy decreases and hence the stability of the corresponding metal hydride decreases.

Q. Can we see stablity trend as on the bond length of the alkali halides?

No, for alkali metal halides, you need to know the entahply of formation data roughly, more the negative value more the stable is the compound
bond length and stability trend is done most preferably in organic chemistry where carbon atom is involved