Acids, Bases , salts

• What is the pH scale used for?

  To measure acidity and alkalinity
• What happens when an acid is neutralized?

  It forms a salt
• What is a corrosive substance?

  An acid with a pH lower than 7
• What causes acidity in a solution?

  A high concentration of hydrogen ions
• What is an alkali?

  A base soluble in water
• What is the pH of pure water?

  7, which is neutral
• What do indicators do in chemistry?

  Change color in acidic or alkaline solutions
• What is the most commonly used indicator in laboratories?

  Universal indicator
• What pH value indicates an acidic solution?

  Below 7
• What pH value indicates a neutral solution?

  A pH of 7
• What pH value indicates an alkaline solution?

  Above 7
• How does universal indicator show pH?

  It changes color based on pH
• What can provide a more accurate pH value than universal indicator?

  A pH probe
• What are the three categories of solutions based on pH?

  • Acidic: pH < 7
  • Neutral: pH = 7
  • Alkaline: pH > 7
• What are the characteristics of acids and bases?

  • Acids: pH < 7, high hydrogen ion concentration
  • Bases: pH > 7, react with acids to form salts
• What is the role of indicators in chemistry?

  • Change color in response to pH
  • Help identify acidic or alkaline solutions
• What is the pH scale used for?

  To measure acidity and alkalinity
• What happens when an acid is neutralised?

  It forms a salt
• What are the classifications of chemicals based on pH?

  • Acidic
  • Neutral
  • Alkaline
• What do atoms consist of?

  A nucleus, protons, neutrons, and electrons
• What ions do acids produce in water?

  Hydrogen ions, H⁺
• What are ions?

  Charged particles formed by atoms
• Why are hydrogen ions sometimes called protons?

  Because they are the same as a hydrogen nucleus
• What is the equation for hydrochloric acid in solution?

  HCl(aq) → H⁺(aq) + Cl^-(aq)
• What do alkalis produce when dissolved in water?

  Hydroxide ions, OH^-
• What is the equation for sodium hydroxide in solution?

  NaOH(aq) → Na⁺(aq) + OH^-(aq)
• How does ammonia behave in solution?

  It produces NH₄⁺ and OH^-
• What is a base?

  It is chemically opposite to an acid
• What is a neutralisation reaction?

  When H⁺ ions react with OH^- ions
• What is the equation for the neutralisation reaction?

  H⁺(aq) + OH^-(aq) → H₂O(l)
• What do hydrochloric acid and sodium hydroxide produce when they react?

  Water and sodium chloride solution
• What ions are involved in the neutralisation of hydrochloric acid and sodium hydroxide?

  H⁺ and OH^- ions
• Why is the process of neutralisation sometimes referred to as 'proton transfer'?

  It involves the loss and gain of hydrogen ions
• What is the pH scale used for?

  To measure acidity and alkalinity
• What happens when an acid is neutralised?

  It forms a salt
• What distinguishes strong acids from weak acids?

  • Strong acids fully dissociate in water
  • Weak acids do not fully dissociate
  • Strong acids produce more H⁺ ions
• What is an example of a strong acid?

  Hydrochloric acid (HCl)
• How many moles of H₊ ions are produced from one mole of HCl?

  One mole of H₊ ions
• What percentage of ethanoic acid molecules dissociate in solution?

  About one percent
• Why do strong acids have lower pH values than weak acids?

  They produce more H₊ ions