Analía Bellizzi – Chemistry Classes

Ronald Reagan Senior High School

  1. Reactions of Elements with Oxygen and Chlorine, and Water:

    a. Reactions with oxygen:

    – Sodium (Na):

    – Magnesium (Mg):

    – Aluminum (Al):

  2. – Phosphorus (P):

  3. – Sulfur (S):

    b. Reactions with chlorine: – Sodium (Na): – Magnesium (Mg): 2 – Aluminum (Al): – Silicon (Si): 4 – Phosphorus (P): 5

    c. Reactions with water (Na and Mg only): – Sodium (Na): 2 – Magnesium (Mg): 2

  4. Variation in Oxidation Number of Oxides and Chlorides: The oxidation number of an element in an oxide or chloride depends on the number of electrons it gains or loses during bonding. In general, the oxidation number of oxygen in compounds is -2, while the oxidation number of chlorine is typically -1. The oxidation number of the other element can vary depending on the compound and its bonding characteristics. For example:

    • In Na2O, Na has an oxidation number of +1, and O has an oxidation number of -2.
    • In Al2O3, Al has an oxidation number of +3, and O has an oxidation number of -2.
    • In MgCl2, Mg has an oxidation number of +2, and Cl has an oxidation number of -1.
  5. Reactions of Oxides with Water and Likely pHs:

    • Na2O + H2O → 2NaOH (alkaline solution)
    • MgO + H2O → Mg(OH)2 (alkaline solution)
    • Al2O3 + 6H2O → 2Al(OH)3 (amphoteric behavior, forms a slightly acidic solution)
    • SiO2 + 2H2O → Si(OH)4 (forms a weakly acidic solution)
    • P4O10 + 6H2O → 4H3PO4 (acidic solution)
    • SO2 + H2O → H2SO3 (forms sulfurous acid, slightly acidic solution)
    • SO3 + H2O → H2SO4 (forms sulfuric acid, acidic solution)
  6. Acid/Base Behavior of Oxides and Hydroxides:

    • Oxides:
      • Na2O: Basic (forms NaOH in water)
      • MgO: Basic (forms Mg(OH)2 in water)
      • Al2O3: Amphoteric (reacts with both acids and bases)
      • P4O10: Acidic (forms H3PO4 in water)
      • SO2: Slightly acidic (forms sulfurous acid in water)
      • SO3: Acidic (forms sulfuric acid in water)
    • Hydroxides:
      • NaOH: Strong base (completely ionizes in water to form Na+ and OH- ions)
      • Mg(OH)2: Weak base (partially ionizes in water to form Mg2+ and OH- ions)
      • Al(OH)3: Amphoteric (reacts with both acids and bases)

I’ll continue with points 5-7 in the next message to ensure we stay within the response limits.

  1. Reactions of Chlorides with Water and Likely pHs:

    • NaCl + H2O → Na+ + Cl- + H2O (neutral solution)
    • MgCl2 + 2H2O → Mg2+ + 2Cl- + 2H2O (neutral solution)
    • AlCl3 + 3H2O → Al(OH)3 + 3H+ + 3Cl- (forms hydrochloric acid, acidic solution)
    • SiCl4 + 4H2O → Si(OH)4 + 4H+ + 4Cl- (forms hydrochloric acid, acidic solution)
    • PCl5 + 4H2O → H3PO4 + 5HCl (forms phosphoric acid and hydrochloric acid, acidic solution)
  2. Explanation of Variations and Trends in Terms of Bonding and Electronegativity:

    • The variation in oxidation numbers and chemical properties of oxides and chlorides can be explained by differences in bonding and electronegativity. For example, oxides with more covalent character, like SiO2 and P4O10, tend to be acidic, while those with more ionic character, like Na2O and MgO, tend to be basic. Similarly, chlorides with higher electronegativity differences, like AlCl3 and PCl5, are more likely to be acidic, while those with lower differences, like NaCl and MgCl2, are neutral.
  3. Types of Chemical Bonding in Chlorides and Oxides:

    • Chlorides: Chlorides typically exhibit ionic bonding, where metal cations are attracted to chloride anions. However, some chlorides, like SiCl4 and PCl5, can exhibit covalent bonding due to the electronegativity differences between silicon or phosphorus and chlorine.
    • Oxides: Oxides can exhibit various types of bonding depending on the elements involved. Metal oxides, like Na2O and MgO, tend to exhibit ionic bonding, while non-metal oxides, like SO2 and SO3, exhibit covalent bonding. Some oxides, like Al2O3, exhibit both ionic and covalent bonding and are considered amphoteric.