Analía Bellizzi – Chemistry Classes

Ronald Reagan Senior High School

GROUP II SUMMARY

    1. Reactions of elements with oxygen, water, dilute hydrochloric acid, and sulfuric acid:

      • Reaction with Oxygen: Many elements react with oxygen to form oxides.
      • The general equation is:
          • Element+Oxygen→Oxide

      • Reaction with Water: Some metals react with water to form metal hydroxides and hydrogen gas.
      • The general equation is:
        • Metal+Water→Metal Hydroxide+Hydrogen Gas

      • Reaction with Dilute Hydrochloric Acid: Some metals react with dilute hydrochloric acid to form metal chlorides and hydrogen gas.
      • The general equation is:
        • Metal+Dilute HCl→Metal Chloride+Hydrogen Gas

      • Reaction with Dilute Sulfuric Acid: Most metals react with dilute sulfuric acid to form metal sulfates and hydrogen gas.
      • The general equation is:
        • Metal+Dilute H2SO4→Metal Sulfate+Hydrogen Gas

    2. Reactions of oxides, hydroxides, and carbonates with water and dilute hydrochloric and sulfuric acids:

      • Reaction with Water: Metal oxides and metal hydroxides react with water to form metal hydroxides.
      • The general equation is:
        • Metal Oxide +Water→Metal Hydroxide

      • Reaction with Dilute Hydrochloric Acid: Metal oxides and metal hydroxides react with dilute hydrochloric acid to form metal chlorides and water.
      • The general equation is:
        • Metal Oxide or Hydroxide+Dilute HCl→Metal Chloride+Water

      • Reaction with Dilute Sulfuric Acid: Metal oxides and metal hydroxides react with dilute sulfuric acid to form metal sulfates and water.
      • The general equation is:
        • Metal Oxide or Hydroxide+Dilute H2SO→Metal Sulfate+Water

      • Reaction of Carbonates: Metal carbonates react with dilute acids to form metal salts, carbon dioxide, and water.
      • The general equation is:
        • Metal Carbonate+Dilute Acid→Metal Salt+Carbon Dioxide+Water

    3. Thermal decomposition of nitrates and carbonates:

      • Nitrates: Metal nitrates decompose upon heating to form metal nitrites, oxygen, and sometimes nitrogen dioxide gas.
      • The general equation is:
        • Metal Nitrate→Metal Nitrite+Oxygen (and possibly NO2 gas)
        • Carbonates: Metal carbonates decompose upon heating to form metal oxides, carbon dioxide, and sometimes water.
        • The general equation is:
          • Metal Carbonate→Metal Oxide+Carbon Dioxide (and possibly water)

          • Generally, the thermal stability of nitrates decreases down the group due to the increasing size of the metal cation and weaker metal-nitrogen bonds

    4. Trends in physical and chemical properties:

      • Reactivity with Oxygen: Generally, reactivity increases down the group for metals. 
      • Reactivity with water and acids: Generally, reactivity increases down the group for metals. 
      • Thermal stability: Thermal stability of nitrates generally decreases down the group, while carbonates’ thermal stability increases down the group for alkali metals and decreases for alkaline earth metals.
    5. Variation in solubilities of hydroxides and sulfates:

        • Solubility of Hydroxides: Solubility generally increases down the group for alkaline earth metals and decreases down the group for transition metals.
        • Solubility of Sulfates: Solubility generally decreases down the group for both alkaline earth metals and transition metals.
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These trends are based on factors like ion size, charge, and lattice energy.