JEE Main2013Chemistrys Block ElementsActual
Equimolar solutions of the following compounds are prepared separately in water. Which will have the lowest pH value ?
Options
- ABeCl ₂
- BSrCl ₂
- CCaCl ₂
- DMgCl ₂
Correct answer
A. BeCl ₂
Step-by-step solution
Metal halide on hydrolysis with water form corresponding hydroxides. The basic strength of hydroxide increases as we move down in a group. This is because of the increase in size which results in decrease of ionization energy which weakens the strength of M - O bonds in MOH and thus increases the basic strength. aligned & Be ( OH )₂ Mg ( OH )₂ & Amphoteric Weak base & Ca ( OH )₂ Sr ( OH )₂ Ba ( OH )₂ & aligned Hence, Be ( OH )₂ will have lowest pH .