Credit will be given for strict adherence to instructions, for observations precisely recorded, and for accurate inferences. All tests, observations, and inferences must be clearly entered in your answer book, in ink, at the time they are made.
C Is an inorganic salt. D is an organic compound. Carry out the following exercises on C and D. Record your observations and identify any gases evolved. State the conclusion you draw from the result of each test.
(a) (i) Put C in a test tube and add about 10 cm\(^3\) of distilled water. Stir well.
(ii) Divide the resulting solution into two portions. To the first portion add sodium hydroxide solution in drops and then in excess.
(iii) To the second portion add dilute trioxonitrate (V) acid. Then add silver trioxonitrate (V) solution followed by aqueous ammonia in excess. tube and odd about 2- 5 cm\(^3\) of ‘Xn’.
(ii) Identify the functional group present in D.
Explanation
| Test | Observation |
Inference |
| (i) C + 10cm\(^3\) of water | Dissolves forming a solution | C is soluble in water |
| (ii) Solution C + NaOH\(_{(aq)}\) in drops and excess | White precipitate which is insoluble in excess | Ca\(^{2+}\) is present |
|
iii) Solution C + HNO\(_{3(aq)}\) + AgNO\(_{3(aq)}\) + NH\(_{3(aq)}\) in excess |
No visible reaction. A white precipitate formed. The precipitate is soluble |
Cl\(^{-1}\) present Cl\(^{-}\) confirmed |
|
(iv) D + NaHCO\(_3\) |
Effervescence occurs, colourless gas evolved which turns lime water milky | D is an organic acid or an alkanoic acid |