(a)(i) Give one laboratory use of activated charcoal
(ii) A piece of phosphorus and some magnesium ribbon were burnt in two separate jars of oxygen. Water was then added to dissolve the product. State the action of litmus on each of the resulting solutions
(b) Give one chemical test to distinguish between CH\(_3\)CH\(_2\)OH and CH\(_3\)COOH.
(c) Describe how you would dilute accurately a solution containing 0.10 mole of the solute per dm\(^3\) of solution to 0.010M.
Explanation
(a)(i) For removing colouring matter or for absorbing gases.
(ii) Solution of magnesium ash turns red litmus blue. MgO + H\(_2\)O = Mg(OH)\(_2\). Solution of phosphorus fumes turns blue litmus red
(b) Add Na\(_2\)CO\(_{3(aq)}\) or NaHCO\(_{3(aq)}\) separately.
- CH\(_3\)COOH gives a colourless gas that turns lime water milky i.e. CO\(_3\)
- CH\(_3\)CH\(_2\)OH gives no visible reaction. We can also use the acidified KMnO\(_4\) rxn, or iodoform rxn or litmus test to distinguish
(c) A stated volume of the solution is pipetted into a clean 250cm\(^3\) volumetric flask. Distilled water is added and the solution is made up to the mark with more distilled water by means of dropping pipette.