Complete the following questions as holiday homework. 1. The titration curve in the graph below shows the change in pH as a solution of 0.10 M sodium hydroxide is added to a 20.00 mL solution of 0.10 M hydrochloric acid. 124 10 8+ equivalence point at pH 7.0 pH 6- 4 2 20 Volume of 0.10 M NaOH (ml.) The titration is repeated using 0.20 M sodium hydroxide solution. Which one of the following statements about the second titration is correct? A. The equivalence point occurs when 10 mL of NaOH is added and the pH is then 7. B. The equivalence point occurs when 10 mL of NaOH is added and the pH is then greater than 7. C. The equivalence point occurs when 40 mL of NaOH is added and the pH is then 7. D. The equivalence point occurs when 40 mL of NaOH is added and the pH is then greater than 7. 2. A volumetric analysis was used to determine the ammonia content of a window cleaner. 0.413 g of a window cleaner was placed in a volumetric flask and the volume made up to 250.0 mL with deionised water. 20.00 mL of this diluted window cleaner was pipetted into a conical flask and several drops of indicator added. 16.59 mL of 0.100 m hydrochloric acid was added from a burette to reach the endpoint of the titration. Which of the following correctly identifies the quantities in this experiment corresponding to each of the terms shown? Aliquot Titre Standard solution A. 20.00 mL 16.59 mL 250.0 mL diluted cleaner B. 250.0 mL 16.59 mL 250.0 mL diluted cleaner c. 20.00 mL 16.59 mL 0.100 M HCI D. 16.59 mL 20.00 mL 0.100 M HCI 3. Five test-tubes each contains the same solution, which has a pH 5.0. A different indicator is added to the solution in each test-tube, as shown in the table below. Use the indicator colour chart on page 2 of this booklet to find the colour of each solution after the indicator was added. Indicator Colour after adding indicator Alizarin yellow Bromothymol blue Methyl red Methyl orange Phenolphthalein