chem changes

• What is the first metal in the reactivity series?

  Potassium
• Which metal is less reactive than zinc?

  Iron
• What does the reactivity series help predict?

  Products of aqueous reactions
• How are more reactive metals extracted?

  By electrolysis
• What happens in a displacement reaction?

  A more reactive metal displaces a less reactive metal
• What do most metals react with acids to produce?

  A salt and hydrogen
• What do metal carbonates produce when they react with acids?

  A salt, carbon dioxide, and water
• Why do Group I metals displace hydrogen?

  They are more reactive than hydrogen
• What is oxidation defined as?

  Loss of electrons
• What is reduction defined as?

  Gain of electrons
• What is produced when an acid reacts with an alkali?

  A salt and water
• What is the general equation for neutralization?

  Acid + Alkali → Salt + Water
• What salt is produced from hydrochloric acid and sodium hydroxide?

  Sodium chloride
• How can you obtain crystals of dissolved salt?

  By heating gently to evaporate water
• What is the pH of water?

  7
• Why does an acid have a pH smaller than 7?

  Due to its H⁺ ions
• Why does an alkali have a pH greater than 7?

  Due to its OH⁻ ions
• What does the pH scale indicate?

  Concentration of H⁺ or OH⁻ ions
• What does a universal indicator do?

  Indicates pH by changing color
• What color does a strong acid turn a universal indicator?

  Red
• How does a strong acid differ from a weak acid at the same concentration?

  It has a lower pH
• What happens to a strong acid in solution?

  It dissociates more completely
• What are the key points of the reactivity series?

  • Lists metals in order of reactivity
  • More reactive metals extracted by electrolysis
  • Less reactive metals extracted by displacement
  • Helps predict reaction products
• What are the products of neutralization reactions?

  • Salt
  • Water
• What is the significance of the pH scale?

  • Measures acidity or alkalinity
  • Acid: pH < 7
  • Alkali: pH > 7
  • Neutral: pH = 7
• What are the characteristics of strong and weak acids?

  • Strong acids: lower pH, dissociate completely
  • Weak acids: higher pH, dissociate partially