Acids, Bases and their Reactants

• What does the pH scale measure?

  Acidity or alkalinity of a solution
• What is the pH value of a neutral solution?

  7
• What do acids form in water?

  H+ ions
• What do alkalis form in water?

  OH- ions
• How are alkalis defined in relation to bases?

  Alkalis are soluble bases
• What are the two ways to measure pH?

  • Universal indicator: changes color for pH
  • pH probe: gives accurate pH value
• What does a universal indicator provide?

  An approximate pH value
• What is the general equation for neutralisation reactions?

  acid + base → salt + water
• What are the products of neutralisation reactions?

  Salt and water
• What happens to H+ and OH- ions during neutralisation?

  They form water (H₂O)
• How do you determine the formula of a salt?

  Balance the charges of the ions
• What is produced when an acid reacts with a metal carbonate?

  Salt, water, and carbon dioxide
• What acid produces chloride salts?

  HCl
• What acid produces sulfate salts?

  H₂SO₄
• What acid produces nitrate salts?

  HNO₃
• What does the first part of a salt's name come from?

  The positive ion in the base
• What is produced when an acid reacts with a metal oxide?

  Salt and water
• What is produced when an acid reacts with a metal hydroxide?

  Salt and water
• How are soluble salts made from acids?

  • Add metals or insoluble metal compounds to acids
  • Filter off excess solid
  • Crystallise remaining salt solution