page 02 SECTION 1 — 30 marks Attempt ALL questions 1. In an emission spectrum of mercury, the line at 310 nm is due to A energy from the ultraviolet region of the electromagnetic spectrum being absorbed B energy from the ultraviolet region of the electromagnetic spectrum being released C energy from the visible region of the electromagnetic spectrum being absorbed D energy from the visible region of the electromagnetic spectrum being released. 2. In which of the following changes would heating to constant mass allow the mass of water produced to be determined? A CH3CH2OH(ℓ)  ↓  C2H4(g)  +  H2O(ℓ) B CH4(g)  +  2O2(g)  ↓  CO2(g)  +  2H2O(ℓ) C KOH(aq)  +  HCl(aq)  ↓  KCl(aq)  +  H2O(ℓ) D Na2CO3.10H2O(s)  ↓  Na2CO3(s)  +  10H2O(ℓ) 3. Which of the following reagents would be most suitable for the gravimetric determination of magnesium ions in water? A Sodium nitrate B Silver(I) nitrate C Sodium carbonate D Silver(I) carbonate 4. Hund’s rule states that A electrons occupy degenerate orbitals singly with parallel spins before pairing B no two electrons in an atom can have the same set of four quantum numbers C electrons occupy orbitals in order of increasing energy D the energy of an electron in an atom is quantised.