Question 1 Report
(a)(i) Define each of the following terms: I. normal salt. II. acid salt.
(ii) Tetraoxosulphate (VI) acid and sodium hydroxide react to produce salt and water. Write a balanced chemical equation fir the formation of: I. a normal salt; II. an acid salt.
(b)(i) Explain briefly the term acid-base indicator.
(ii) Copy and complete the following table.
| Indicator |
, Colour in acidic medium | , Colour in basic medium |
| Methyl orange |
||
| Phenolphthalein |
(iii) For each of the following titrations, state the most suitable indicator: I. strong acid against strong base; II. strong acid against weak base; iii. weak acid against strong base.
(c) Baking soda and hydrochloric acid react according to the following equation:
NaHCO\(_{3(aq)}\) + HCI\(_{(aq)}\) ---> NaCl\(_{(aq)}\) CO\(_{2(g)}\) + H\(_2\)O\(_{(l)}\). Calculate the mass of baking soda that would produce 10g of ccrbon (IV) oxide. [H = 1.00, C = 12.0, 0 = 16.0, Na = 23.0]
(d) Give a reason why a given mass of sodium hydroxide pellets cannot be used to prepare a standard solution.
NaHCO\(_3\) + HCI --> NaCI + CO\(_2\) + H\(_2\)O
84g NaHCO\(_3\) --> 44g CO\(_2\)
Xg --> 10g CO\(_2\)
Xg = \(\frac{84 \times 10}{44}\)
= 19.09g
= 19.1g.
(d) give a reason why a given mass of sodium hydroxide pellets cannot be used to prepare a standard solution: Sodium hydroxide absorbs water/deliquescent and absorbs carbon IV oxide from air/and this would make mass taken unreliable/add to its mass.