Acids and bases (get the grade)

• What is the definition of bases in chemistry?

  Water-soluble alkalis
• How are the terms alkali and base related?

  All bases are alkalis, but not vice versa
• Why can acids and alkalis be dangerous?

  pH levels that are too low or high
• What does the pH scale measure?

  Acidity and alkalinity
• What is the pH range of the pH scale?

  0 to 14
• What indicates a higher concentration of H+ ions?

  A lower pH value
• What indicates a higher concentration of OH- ions?

  A higher pH value
• What is the relationship between H+ and OH- ions in pure water?

  Their concentrations are equal
• What happens to the pH when an acid is diluted?

  The pH rises towards 7
• What happens to the pH when an alkali is diluted?

  The pH falls towards 7
• What do soluble non-metal oxides produce when dissolved in water?

  Acidic solutions
• What do soluble metal oxides produce when dissolved in water?

  Alkaline solutions
• What is a neutralisation reaction?

  Reaction between an acid and a base
• What products are formed in a neutralisation reaction?

  Salt and water
• What does a reaction between a metal oxide and an acid produce?

  Salt and water
• What does a reaction between a metal hydroxide and an acid produce?

  Salt and water
• What does a reaction between a metal carbonate and an acid produce?

  Salt, water, and carbon dioxide
• What type of salts are produced from hydrochloric acid?

  Chloride salts
• What type of salts are produced from sulphuric acid?

  Sulphate salts
• What type of salts are produced from nitric acid?

  Nitrate salts
• What are spectator ions?

  Ions that do not participate in reactions
• How is a net ionic equation created?

  By eliminating spectator ions
• What are titrations used for?

  Measuring solution volume for reactions
• What is a standard solution?

  A solution of known concentration
• What is the purpose of an indicator in titrations?

  To show when the end point is reached
• When are titre volumes considered concordant?

  When measurements are within 2cm^3
• What is the method for determining the concentration of an acid using titration?

  1. Clean and set up equipment
  2. Measure known volume of acid into conical flask
  3. Add indicator to alkali standard solution
  4. Wash burette with standard solution
  5. Pour standard solution into burette
  6. Record volume from bottom of meniscus
  7. Open tap while swirling flask
  8. Measure volume when acid changes color
  9. Repeat until concordant results are obtained
  10. Calculate the concentration of the acid
• What are common acids and alkalis?

  Common acids:

  • Hydrochloric acid (HCl)
  • Nitric acid (HNO3)
  • Sulphuric acid (H2SO4)

  
  

  Common alkalis:

  • Calcium hydroxide (Ca(OH)2)
  • Sodium hydroxide (NaOH)
  • Lithium hydroxide (LiOH)
• What are the key points about the pH scale?

  • Measures acidity and alkalinity
  • Ranges from 0 to 14
  • Concentration of H+ and OH- ions in water is equal