Unit 1 👩‍🔬acids and bases 👩‍🔬

• What is the formula to calculate percentage composition by mass?

  % by mass = (mass of component / total mass) x 100
• What pH value indicates an acidic solution?

  A pH value less than 7
• What pH value indicates an alkaline solution?

  A pH value greater than 7
• What pH value indicates a neutral solution?

  A pH value of 7
• What happens to the concentration of a solution when it is diluted?

  The concentration decreases
• How does the pH change when an acid is diluted?

  The pH increases
• How does the concentration of hydrogen ions change when an acid is diluted?

  The concentration of hydrogen ions decreases
• What happens to the pH when an alkali is diluted?

  The pH value decreases
• How does the concentration of hydroxide ions change when an alkali is diluted?

  The concentration of hydroxide ions decreases
• What is the chemical formula for hydrochloric acid?


  HCl
• What is the chemical formula for nitric acid?

  HNO₃
• What is the chemical formula for sulfuric acid?

  H₂SO₄
• What is the chemical formula for ethanoic acid?

  CH₃COOH
• What is the chemical formula for phosphoric acid?

  H₃PO₄
• How are acidic solutions formed?

  By dissolving non-metal oxides in water
• What are common non-metal oxides that form acidic solutions?

  Carbon dioxide and sulfur dioxide
• What is the chemical formula for lithium hydroxide?

  LiOH
• What is the chemical formula for sodium hydroxide?

  NaOH
• What is the chemical formula for potassium hydroxide?

  KOH
• What is the chemical formula for calcium hydroxide?

  Ca(OH)₂
• How are alkaline solutions formed?

  By dissolving soluble metal oxides in water
• What is the effect of insoluble metal oxides on the pH of water?

  They will not affect the pH of water
• What is the process of an acid-base titration?

  • Determine unknown concentration of acid or base
  • Measure volumes used during neutralization
  • Add an indicator to show the end-point
• What is the relationship between the concentrations and volumes of acid and alkali in titration calculations?

  • Concentration of acid x Volume of acid = Concentration of alkali x Volume of alkali
  • Formula: $C_i V_i =$$C_z V_z$
  • Number of moles: $n_1 =$$n_2$
• What is the pH scale range?

  From below 0 to above 14
• How can pH be measured?

  Using a pH meter or an indicator
• What does a pH meter provide?

  An electronic reading of pH
• How can the pH value be determined using an indicator?

  By matching the color on a pH color chart
• What are the characteristics of acidic, neutral, and alkaline solutions on the pH scale?

  • Acidic: pH < 7
  • Neutral: pH = 7
  • Alkaline: pH > 7
• What is the dissociation of water?

  Water dissociates to produce H⁺ and OH⁻ ions
• Why is water a poor conductor of electricity?

  Because it mainly consists of molecules with few ions
• What defines an acidic solution in terms of ion concentration?

  It has a greater concentration of hydrogen ions compared to hydroxide ions
• What defines an alkaline solution in terms of ion concentration?

  It has a greater concentration of hydroxide ions compared to hydrogen ions
• What is the relationship between hydrogen and hydroxide ions in acidic, neutral, and alkaline solutions?

  • Acid: Greater concentration of H⁺
  • Neutral: Equal concentration of H⁺ and OH⁻
  • Alkali: Greater concentration of OH⁻
• What are alkaline solutions made from?

  They are made by dissolving soluble metal oxides in water.
• Why do insoluble metal oxides not affect the pH of water?

  Because they do not dissolve in water.
• What are some common alkalis and their chemical formulas?

  • Lithium hydroxide: LiOH
  • Sodium hydroxide: NaOH
  • Potassium hydroxide: KOH
  • Calcium hydroxide: Ca(OH)₂
• What is a base?

  A base is any substance that neutralizes an acid.
• How does a base neutralize an acid?

  By accepting hydrogen ions from the acid to form water.
• What are common types of bases?

  • Metal oxides
  • Metal hydroxides
  • Metal carbonates
  • Ammonia