Beryllium and magnesium do not give colour to flame whereas other alkaline earth metals do so. Why?
Comment on each of the following observations:
(where M = Ca, Sr or Ba) is nearly constant.
Explain why alkaline earth metals are poor reducing agents as compared to alkali metals.
Explain the trend of solubility of carbonate, sulphates and hydroxides of alkaline earth metals ?
Account for the following:
(i) Be(OH)2 is amphoteric while Mg(OH)2 is basic.
(ii) Be(OH)2 is insoluble but Ba(OH)2 is fairly soluble in water.
(i) This is because I.E. of Mg < I.E. of Be. So bond M – OH can break more easily in Mg(OH)2 than in Be(OH)2.
(ii) This is because with the increase in size (from Be to Ba), the lattice enthalpy decreases significantly but hydration enthalpy remains almost constant.