(a) In the laboratory preparation of crystals of CuSO\(_4\), a green powder Q was added to dilute H\(_2\)SO\(_4\), and stirred. Effervescence occurred and a gas R was given off which turned lime water milky. Excess Q was removed from the mixture. The solution of Cu\(_2\)SO\(_4\) was concentrated to half its original volume and allowed to stand.
(i) What is substance Q?
(ii) Name gas R
(ii) Why was excess Q used?
(iv) How would you know that the reaction is complete?
(v) What method was used to remove excess Q? (vi) Why was the solution of CusO\(_4\) not heated to dryness?
(b) Name the reagent(s) used for testing each of the following substances in the laboratory: (i) Water; (i) Primary alkanol.
Explanation
(a)(i) Q is copper (II) trioxocarbonate (IV)
(ii) R is carbon (IV) oxide
(iii) Excess Q was used to ensure that all the acid reacted
(iv) When there is no more effervescence.
(v) Filtration.
(b)(i) White anhydrous copper (II) teraoxosulphate (VI).
(ii) Alkaline iodine solution, or acidified potassium tetraoxomanganate (VIl).