Concentrations and strengths of acids - Higher

• What is the purpose of indicators in chemistry?

  Indicators are used to determine whether a solution is acidic or alkaline.
• What do acids produce when they react with metals, bases, and carbonates?

  Acids produce salts when they react with metals, bases, and carbonates.
• What is neutralisation in chemistry?

  Neutralisation is the reaction between an acid and a base.
• What are the components of a solution?

  • Solute: The dissolved substance.
  • Solvent: The liquid in which the solute dissolves.
  • Solution: The mixture formed by the solute and solvent.
• How is the concentration of a solution defined?

  The concentration of a solution is a measure of the mass or amount of solute dissolved in a given volume of solvent or solution.
• What does a dilute solution contain?

  A dilute solution contains a relatively small amount of dissolved solute.
• What does a concentrated solution contain?

  A concentrated solution contains a relatively large amount of dissolved solute.
• How can the term 'dilute' be used in chemistry?

  'Dilute' can describe the concentration of a solution or the process of adding more water to decrease concentration.
• What is a strong acid?

  A strong acid completely dissociates into ions in solution.
• Give an example of a strong acid.

  Hydrochloric acid is an example of a strong acid.
• What characterizes weak acids?

  Weak acids only partially dissociate in solution.
• What is an example of a weak acid?

  Ethanoic acid is an example of a weak acid.
• What does the symbol ⇌ indicate in a chemical equation?

  The symbol ⇌ indicates that the reaction is reversible and does not go to completion.
• How is pH related to hydrogen ion concentration?

  The pH of a solution is a measure of its concentration of hydrogen ions.
• What pH value indicates an acidic solution?

  A pH value below 7 indicates an acidic solution.
• What pH value indicates an alkaline solution?

  A pH value above 7 indicates an alkaline solution.
• How does the concentration of hydrogen ions affect the pH of a solution?

  The higher the concentration of H⁺ ions in an acidic solution, the lower the pH.
• What happens to the pH if the hydrogen ion concentration increases by a factor of 10?

  The pH of the solution decreases by 1 unit.
• How does the concentration of OH^- ions affect the pH of alkaline solutions?

  The higher the concentration of OH^- ions in an alkaline solution, the higher the pH.
• If a solution of 1 g/dm³ hydrochloric acid has a pH of 1.6, what will its pH be when diluted to 0.1 g/dm³?

  The pH will increase by 1 to 2.6.
• If a solution of 2 g/dm³ hydrochloric acid has a pH of 1.3, what will its pH be when diluted to 0.02 g/dm³?

  The pH will increase by 2 to 3.3.
• What is the relationship between acid concentration and pH?

  • More concentrated acid solutions have lower pH values.
  • If hydrogen ion concentration increases by a factor of 10, pH decreases by 1 unit.
• What are the characteristics of strong and weak acids?

  • Strong acids: Completely dissociate in solution (e.g., HCl).
  • Weak acids: Partially dissociate in solution (e.g., CH₃COOH).