Chemistry assignment for grade 12 in 2016 E.C 1. Calculate the concentration of HCOOH, H and HCOO at equilibrium and calculate the pH of a 0.1 M formic acid (HCOOH) solution. The Ka of HCOOH is 1.7x104. 2. What is the pH of a 0.40 M ammonia solution? The K₁ of NH3 is 1.8x105. 3. Balance the following equation by the half-reaction method. A. HsIO6+ Cr→ IO3 + Cr3+ (In an acidic medium) B. NO3 + H2O2 NO + O2 (In basic medium) 4. Calculate the masses of Na and Cl₂ gas would be produced if a current of 25 A is passed for 8 hrs in to molten NaCl. 5. Calculate the mass of Cu and the volume of O2 (at 25 C° and 760 mmHg) that would be produced by passing a current of 0.5 A through a CuSO4 solution between Pt electrodes for 3 hrs. ​