(iii) 2 moles of carbon are burnt in 16 g of dioxygen. Their higher charge densities (as compared to alkali metals) account for higher lattice energies. Ionic mobility also becomes lesser. Lattice energy of Na2CO3 is higher than that of Li2CO3. 1:56 000+ LIKES. Solubility of sulphates: The solubility of sulphates of alkaline earth metals decreases as we move down the group from Be to Ba due to the reason that ionic size increases down the group. When an alkali metal dissolves in liquid ammonia the solution can acquire different colours. Solubility of hydroxides of alkali metals is higher due to lower ionization enthalpy. Calculate the concentration of hydrogen ion in it. Explain why is sodium less reactive than potassium? Arrange the following type of radiations in increasing order of frequency: Write chemical reactions to show the amphoteric nature of water. Sodium hydroxide, NaOH, also known as caustic soda or lye, is of great industrial importance. It is the main pigment for the absorption of light in plants. Let x is the oxidation state of Na in Na2O2. The oxides of alkali metals are very basic in nature. Solubility in liquid ammonia. Describe the importance of the following: (i) limestone (ii) cement (iii) plaster of paris. U can like my Facebook page ie. Halides of Alkaline Earth Metals Fluorides are insoluble in water. 800+ SHARES. Solubility of hydroxides. This page looks at the solubility in water of the hydroxides, sulphates and carbonates of the Group 2 elements - beryllium, magnesium, calcium, strontium and barium. Compare the alkali metals and alkaline earth metals with respect to. Halides are hygroscopic and have the water of crystallization in their solid state (CaCl 2.6H 2 O). Potassium – These activate many enzymes and participate in the oxidation of glucose to produce ATP. This causes their first ionization enthalpies to be higher than that of alkali metals. This is due to the high lattice energies of alkaline earth metals. Caustic soda – is used in manufacturing soap paper, artificial silk. Why are potassium and cesium, rather than lithium used in photoelectric cells? Hence, sodium is more useful. The solubility in water of the other hydroxides in this group increases with increasing atomic number. Lattice energy of BeO is comparatively higher than hydration energy. (ii) 1 mole of carbon is burnt in 16 g of dioxygen. Which of the alkali metal is having least melting point? All of the alkaline earths react with halogens to form halides. Why are alkali metals not found in nature? (ii) Determine the molality of chloroform in the water sample. (i) ionization enthalpy (ii) basicity of oxides (iii) solubility of hydroxides. The sulfates compounds of the alkaline earth metals show decreasing solubility as you go down the group. Group 2: The Alkaline Earth Metals Atomic radius Atomic radius increases down Group 2. D. Thermal stability of carbonates. Hence, ionization enthalpy of potassium is less than that of sodium, potassium is more reactive than sodium. Solubility in water : Alkaline earth metal hydroxides are less soluble in water as compared to the alkali metal hydroxides. Li is the smallest so it has highest charge density and hence attracts water molecules more strongly. If its K.E. Also, they lose their only valence electron easily as they attain stable noble gas configuration after losing it. Hydroxides of alkaline earth metals (Group II) OH – with Ca 2+, Sr 2+, etc. The carbonates of all Group 2 metals are insoluble. This trend can be explained by the decrease in the lattice energy of the hydroxide salt and by the increase in the coordination number of … Which one of the following alkali metals gives hydrated salts? The hydroxides of the alkali metals, lithium, sodium, potassium, rubidium, and cesium, are the strongest bases and the most stable and most soluble of the hydroxides. Alkali metals are prepared by electrolysis of their fused chlorides? What are the common physical and chemical features of alkali metals? The hydroxides formed by Calcium(Ca),Magnesium(Mg),Beryllium(Be),Strontium(Sr),Barium(Ba So the chemical formula for alkaline earth hydroxides can be: Smaller the size of the ion, more highly it is hydrated and greater is the mass of the hydrated ion. Describe the importance of the following: (i) limestone (ii) cement (iii) plaster of paris. This is the reason why, these metals are not obtained by chemical reduction methods. They are less electropositive than alkali metals. Due to which, K and Cs are used in photoelectric cells rather than lithium. It undergoes hydrolysis to produce strong base NaOH and its aqueous solution is alkaline in nature. The hydroxides include the familiar alkalies of the laboratory and industrial processes. What are the harmful effects of photochemical smog and how can they be controlled? The hydroxides of alkali metals are more soluble than those of alkaline earth metals.