Polymer made from the styrene monomer: [[Image:sci_chem_pastpapers_2004hsc_17c_3.png|Polystyrene]] OR sometimes drawn as, (The above method is better though. See 2004 HSC Notes from the Examination Centre Chemistry, – p7.) Question 18: Question 19: Question 20: Question 21: (a) Qualitative analysis refers to observing qualities, properties or observations and making a judgement based on these observations. Quantitative analysis refers to performing numerical calculations based on data from experiment or other to make a judgement. (b) (c) Question 22: (a) Amphiprotic substances are able to act as both proton donors and proton acceptors. (b) H<sub>2</sub>PO<sub>4</sub><sup>–</sup> + H<sub>2</sub>O &rarr; H<sub>3</sub>O<sup>+</sup> + HPO<sub>4</sub><sup>2-</sup> H<sub>2</sub>PO<sub>4</sub><sup>–</sup> + H<sub>3</sub>O<sup>+</sup> &rarr; H<sub>2</sub>O + H<sub>3</sub>PO<sub>4</sub> Question 23: Question 24: (a) <math>n = cv</math> <math>n = 0.01 \times 10 = 0.1</math> <math>c = \frac {n}{v} = \frac {0.1}{10 + 90} = 0.001</math> mol L<sup>-1</sup> <math>pH = -log_10 0.001 = 3.00</math> (b) They are used as food additives as they (c) Question 25: Question 26: Question 27: SECTION II: Question 28 Industrial Chemistry: – Question 29 Shipwrecks, Corrosion and Conservation: – Question 30 The Biochemistry of Movement: – Question 31 The Chemistry of Art: – Question 32 Forensic Chemistry: –
Polymer made from the styrene monomer: [[Image:sci_chem_pastpapers_2004hsc_17c_3.png|Polystyrene]] OR sometimes drawn as, (The above method is better though. See 2004 HSC Notes from the Examination Centre – Chemistry, p7.) Question 18: Question 19: Question 20: Question 21: (a) Qualitative analysis refers to observing qualities, properties or observations and making a judgement based on these observations. Quantitative analysis refers to performing numerical calculations based on data from experiment or other to make a judgement. (b) (c) Question 22: (a) Amphiprotic substances are able to act as both proton donors and proton acceptors. (b) H<sub>2</sub>PO<sub>4</sub><sup>–</sup> + H<sub>2</sub>O &rarr; H<sub>3</sub>O<sup>+</sup> + HPO<sub>4</sub><sup>2-</sup> H<sub>2</sub>PO<sub>4</sub><sup>–</sup> + H<sub>3</sub>O<sup>+</sup> &rarr; H<sub>2</sub>O + H<sub>3</sub>PO<sub>4</sub> Question 23: Question 24: (a) <math>n = cv</math> <math>n = 0.01 \times 10 = 0.1</math> <math>c = \frac {n}{v} = \frac {0.1}{10 + 90} = 0.001</math> mol L<sup>-1</sup> <math>pH = -log_10 0.001 = 3.00</math> (b) They are used as food additives as they (c) Question 25: Question 26: Question 27: SECTION II: Question 28 – Industrial Chemistry: Question 29 – Shipwrecks, Corrosion and Conservation: Question 30 – The Biochemistry of Movement: Question 31 – The Chemistry of Art: Question 32 – Forensic Chemistry:
Chemistry_Resources_-_Past_Paper_Solutions.docx