TOLC-vet 2014 acid base question

Practice Question Solving
1

How many of the following are acidic and basic in an aqueous solution?
CO2 MgO HCl Na2O HNO3 NO2 H2SO4 SO2 K2O KOH

Answer: 7 acidic 3 basic

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CO2 + H2O — H2CO3 = Acidic

MgO + 2H2O — Mg(OH)2 + H2 = Basic

HCl + H2O — Cl⁻ + H3O⁺ = Acidic

Na2O + H2O — 2NaOH = Basic

HNO3 + H2O — NO3⁻ + H3O⁺ = Acidic

NO2 + H2O — HNO3⁻ + H⁺ = Acidic

H2SO4 + H2O — H3O⁺ + HSO4⁻ = Acidic

KO2 + H2O — 2KOH = Basic

KOH + H2O — K⁺ + H2O + HO⁻ = Basic

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  1. CO2 (Carbon dioxide): When carbon dioxide is dissolved in water, it forms carbonic acid (H2CO3), which is acidic.
  2. MgO (Magnesium oxide): Magnesium oxide is a metal oxide, and it forms a basic solution when dissolved in water. It reacts with water to form magnesium hydroxide, Mg(OH)2.
  3. HCl (Hydrochloric acid): HCl is a strong acid. When it’s dissolved in water, it ionizes completely to form H+ ions, making the solution acidic.
  4. Na2O (Sodium oxide): Sodium oxide is a metal oxide and it forms a basic solution when dissolved in water. It reacts with water to form sodium hydroxide, NaOH.
  5. HNO3 (Nitric acid): Nitric acid is a strong acid. When it’s dissolved in water, it ionizes completely to form H+ ions, making the solution acidic.
  6. NO2 (Nitrogen dioxide): When dissolved in water, nitrogen dioxide forms nitrous acid (HNO2) and nitric acid (HNO3), both of which are acidic.
  7. H2SO4 (Sulfuric acid): Sulfuric acid is a strong acid. When it’s dissolved in water, it ionizes completely to form H+ ions, making the solution acidic.
  8. SO2 (Sulfur dioxide): When sulfur dioxide is dissolved in water, it forms sulfurous acid (H2SO3), which is acidic.
  9. K2O (Potassium oxide): Potassium oxide is a metal oxide and it forms a basic solution when dissolved in water. It reacts with water to form potassium hydroxide, KOH.
  10. KOH (Potassium hydroxide): Potassium hydroxide is a strong base. When it’s dissolved in water, it ionizes completely to form OH- ions, making the solution basic.
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