(a) An aqueous solution of salt Q was added to excess Sodium trioxocarbonate (V) solution in a test tube. There was effervescence, the test tube became warm and a white precipitate was observed. State three inferences that could be drawn from these observations.
(b) Consider the following salts: NH\(_4\)CI; PbSO\(_4\); NaHCO\(_3\), Cu(NO\(_3\))\(_2\) and ZnCO\(_3\). Select from the list, the salt(s) which;
(i) do not/does not readily dissolve in water;
(i) produce(s) effervescence with dilute mineral acids;
(ii) decompose(s) on heating
(iv) dissolves(s) in water to form an alkaline solution;
(v) sublime(s) on heating.
Explanation
(a) The solution of salt Q was acidic/acid solution
- CO\(_2\)/carbon (IV) oxide was given off
- the reaction was exothermic (i.e. Heat is given off)
- an insoluble compound was formed
(b)(i) PbSO\(_4\) and ZnCO\(_3\)
(ii) NaHCO\(_3\) and ZnCO\(_3\)
(iii) NH\(_4\)Cl, NaHCO\(_3\), Cu(NO\(_3\))\(_2\) and ZnCO\(_3\)
(v) NH\(_4\)Cl