(a) \(_2^4He\) has its outermost / Valence shell fully filled with electrons / has maximum number of electrons in its outermost shell / duplet thus more stable whereas \(_4^9Be\) has incomplete filled outermost / valence shell hence less stable.
(b) (i) 1H - 2 electrons / zero
3Li - 2 electrons
(ii)
1H - it accepts one electron
/ donates one electron
3Li - it loses an electron
to have a duplet shell
(c) - nearness to raw material / feed stock
- nearness to markets
- labour supply
- transportation
- availability of power supply
- government policy
- away from residential areas
- storage facilities for raw materials
- source of water supply
- conducive climate
(d) - saves money / the plant does not have to operate for long to produce
- reduces energy / reaction proceeds at a much lower temperature
- no undesirable products are formed / catalyst is specific in action
(e) From the equation:
8 moles of Cl\(_2\) reacts with 1 mole turpentine
1 mole of Cl\(_2\) = 71 g
8 moles = 8 x 71
= 568 g
\(\frac{21.3}{568}\)g will react with 21.3 x 136
= 5.1 g
OR8 moles of Cl\(_2\) reacts with 1 mole turpentine
8 moles of Cl\(_2\) = 8 x 71
= 568 g
21.3 g of Cl\(_2\) = \(\frac{136}{71 \times 8}\) x 21.3
= 5.1 g
ORMole of Cl\(_2\) = \(\frac{21.3}{71}\)
= 0.3 mole
8 moles Cl\(_2\) \(\to\) 136 g C\(_{10}\)H\(_{16}\)
0.3 mole Cl\(_2 \) = \(\frac{136}{8}\) x 0.3
= 5.1 g
(f) Cracking is the breaking down of long chain hydrocarbons into smaller molecules
by the action of heat and / or in the presence of a catalyst.
(g) - nuclear charge
- atomic size
- electron configuration
(h) Carbohydrates are molecules / organic compounds consisting of carbon, hydrogen and oxygen atoms usually with hydrogen and oxygen atoms in the ratio of 2:1.
(i)
| Sugar | Starch |
| - monosaccharides / low molar Mass | - polysaccharides / high molar mass |
| - single units of specific molecules | - long chains of single sugar molecule/ subunits linked together |
| - general formula C\(_x\)H\(_{2y}\)O\(_{y}\) | - general formula (C\(_6\)H\(_{10}\)O\(_5\))n |
| - crystalline | - amorphous / non crystalline |
| - soluble in water | - insoluble in water |
(j) (i) H\(_2\)CO\(_{3(aq)}\) \(\to\) H\(^+\)\(_{(aq)}\) + HCO\(_{3(aq)}\)\(^{-}\)
OR H\(_2\)CO\(_{3(aq)}\) \(\to\) 2H\(^{+}\)\(_{ (aq) }\) + CO\(_{3(aq)}^{2-}\)
OR H\(_2\)CO\(_{3 (aq)}\) + H\(_2\)O\(_{(l)}\) \(\to\) H\(_3\)O\(^+\)\(_{(aq)}\) + HCO\(_{3 (aq)}^-\)
H\(_2\)CO\(_{3 (aq)}\) + 2H\(_2\)O\(_{(l)}\) \(\to\) 2H\(_3\)O\(^+\)\(_{(aq)}\) + CO\(_{3 (aq)}^{2+}\)
(ii) CH\(_3\)COOH\(_{(aq)}\) + H\(_2\)O\(_{(l)}\) \(\to\) CH\(_3\)COO\(^-_{(aq)}\) + H\(_{3}\)O\(^{+}\)\(_{(aq)}\)
OR CH\(_3\)COOH\(_{(aq)}\) \(\to\) CH\(_3\)COO\(^-_{(aq)}\) + H\(^+_{(aq)}\)
