Starter quiz
- Match the keyword to the correct statement
- acid⇔A solution with a pH of less than 7. ✓
- alkali⇔A soluble base with a pH greater than 7. ✓
- base⇔A substance which reacts with an acid to form a salt and water. ✓
- Which of these statements about chemical reactions are true?
- New products are made when a chemical reaction occurs. ✓
- New reactants are made when a chemical reaction occurs.
- The total mass of reactants is the same as the total mass of the products. ✓
- No new substances are formed when a chemical reaction occurs.
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- What is the result if blue litmus paper is dipped into lemon juice?
- It stays blue.
- It turns red. ✓
- It turns green.
- It turns yellow.
-
- What is the result if red litmus paper is dipped into soapy water?
- It turns blue. ✓
- It stays red.
- It turns green.
- It turns yellow.
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- True or false? Vinegar can be used to neutralise sodium hydroxide.
- True ✓
- False
- Which containers of liquid may require a corrosive hazard label?
- water
- milk
- sulfuric acid ✓
- sodium hydroxide (an alkali) ✓
-
Exit quiz
- Match the keyword to the correct statement.
- pH scale⇔Measures the acidity or alkalinity of solutions. ✓
- neutral⇔A solution that has a pH of 7. ✓
- alkali⇔A solution with a pH of more than 7. ✓
- acid⇔A solution with a pH of less than 7. ✓
- A bee sting is acidic. What colour would universal indicator turn?
- blue
- green
- red ✓
- purple
-
- What does pH stand for?
- potential of hydrogen ✓
- potential of hydroxide
- potential of helium
- potential of harm
-
- Four solutions were tested with universal indicator. Rank the results in terms of acidity. Place the most acidic solution first.
- 1⇔red
- 2⇔orange
- 3⇔yellow
- 4⇔blue
- Select the correct statements about concentration of hydrogen and pH.
- The higher the concentration of hydrogen, the lower the pH. ✓
- The higher the concentration of hydrogen, the higher the pH.
- The lower the concentration of hydrogen, the higher the pH. ✓
- The lower the concentration of hydrogen, the lower the pH.
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- Solution A has a pH of 8 and solution B has a pH which is 1000 times more alkaline. What is the pH of solution B?
- 11 ✓
- 10
- 9
- 7
-
Worksheet
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Lesson Details
Key learning points
- Most acids and alkalis are colourless solutions, so indicators can be used to identify them.
- pH stands for ‘potential of hydrogen’ and acids contain hydrogen.
- The higher the concentration of hydrogen, the lower the pH.
- The pH scale goes up and down in factors of ten, so an acid of pH 2 is ten times more acidic than pH 3.
- A low pH means acidic, a high pH means alkaline and solutions with a pH of 7 are neutral.
Common misconception
The difference between concentrated and dilute vs strong and weak when referring to acids and alkalis (not covered in this lesson).
For acids and alkalis concentration is the amount of hydrogen dissolved in a certain volume of solution. The higher the concentration, the lower the pH. Strong and weak refer to the ability of an acid to release hydrogen (not covered in lesson).
Keywords
Ph scale - A scale from 1 to 14 used to measure the acidity or alkalinity of solutions. pH7 is for neutral solutions.
Acidic - A solution that has a pH of less than 7.
Alkaline - A solution that has a pH of more than 7.
Neutral solution - A solution that has a pH of 7.
Concentration - The amount of chemical dissolved in a certain volume of solution.
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