6.7 Neutralisation

What is the meaning of neutralization?

• Reaction between an acid and metal to form salt and water only.

• Reaction between an acid and an alkali to form salt and hydrogen gas only.

• Reaction between an acid and an alkali to form salt and water only.

• Reaction between acid and metal carbonate to form salt, carbon dioxide and water only.

State the changes in the methyl orange indicator inside the conical flask containing potassium hydroxide solution, KOH when it reaches end point.

• Red to orange

• Yellow to orange

• Red to yellow

• Yellow to orange

50 cm³ of 0.75 mol dm^–3 ammonia solution, NH₃ is titrated with 1.0 mol dm^–3 nitric acid, HNO₃. What is the volume of 1.0 mol dm^–3 nitric acid, HNO₃ that is needed to neutralise the ammonia solution, NH₃?

Calculate the volume of 0.05 mol dm^–3 hydrochloric acid, HCl that exactly neutralizes 25 cm³ of 0.1 mol dm^–3 barium hydroxide solution, Ba(OH)₂.

• 75 cm³

• 125 cm³

• 150 cm³

• 100 cm³

Based on the following chemical equation, 20 cm³ monoprotic acid, HX reacts completely with 10 cm³ of 0.1 mol dm^–3 potassium hydroxide solution, KOH.

HX(aq) + KOH(aq) → KX(aq) + H2O(l)

What is the molarity of this acid?

• 0.05 mol cm^–3

• 5x10^-2 mol dm^–3

• 0.005 mol dm^–3

• 0.10 mol dm^–3

25 cm³ of 0.2 mol dm^–3 sodium hydroxide solution, NaOH is titrated with 0.1mol dm^–3 sulphuric acid, H₂SO₄. What is the volume of sulphuric acid, H₂SO₄ needed to neutralise sodium hydroxide solution, NaOH?

50 cm³ of nitric acid, HNO₃ completely neutralises 50 cm³ of 0.25 mol dm^–3 calcium hydroxide, Ca(OH)₂. Calculate the molarity of the nitric acid, HNO₃.

• 0.005 mol dm^–3

• 0.01 mol dm^–3

• 0.50 mol dm^–3

• 1.00 mol dm^–3

In a titration, 15 cm3 of 0.5 mol dm^–3 sulphuric acid, H₂SO₄ neutralises 20 cm₃ of potassium hydroxide solution, KOH. Calculate the concentration of potassium hydroxide solution, KOH.

• 0.50 mol dm^–3

• 0.55 mol dm^–3

• 0.75 mol dm^–3

• 0.85 mol dm^–3