(a) i) Temporary hardness and permanent hardness.
(ii) Temporary hardness
— Calcium hydrogen rioxocarbonate IV or magnesium hydrogentrioxocarbonate(IV). Permanent hardness
— Calcium etraoxosulphate (VI) or magnesium tetraoxosulphate (VI).
Temporary hardness:
iii) Ca(HCO\(_3\))\(_2\) + Ca(OH)\(_2\) \(\to\) 2CaCO\(_3\) + H\(_2\)O
OR Ca(HCO\(_3\))\(_2\) \(\to\) CaCO\(_3\) + H\(_2\)O + CO\(_2\)
Permanent hardness: CaSO\(_4\) + Na\(_2\)CO\(_3\) \(\to\) CaCO\(_3\) + Na\(_2\)SO\(_4\)
(iv) It forms precipitate of calcium salt or ;cum with soap that waste soap.

(b)(i) 1. Glucose solution —Equal to 7
II. Chlorine water — Less than 7
II. Lime water — Greater than 7
IV. Sour milk — Less than milk.
(ii) I. An acidic oxide reacts with only alkali to form salt and water only while amphoteric oxide react with both acids and alkalis to form salt and water only.
II. A dilute acid contains more water than a concentrated acid.
III. An acid salt contains replacement iydrcgen while a normal salt does not.

(c)(i) Fe\(_{(S)}\) + H\(_2\)SO\(_{4(aq)}\) \(\to\) FeSO\(_{4(aq)}\) + H\(_{2(g)}\) ;
Molar mass of FeSO\(_4\) 56 + 32 + 64 = 152
1 mole of Fe produces 152 mass of FeSO\(_4\) ;
0.5 mole of Fe will produce \(\frac{0.5 \times 152}{1}\) = 76g
ii) Monoclinic and rhombic sulphur

(d)(i) When a piece of damp starch - iodide paper is plunged in a gas ar of chlorine, the paper turns from white to blue or blue black.
(ii) Chlorine displaces iodine from starch odide. The iodine reacts with starch to form a blue black complex.
(iii) Products formed are hydrogen Chloride and nitrogen.