Correct Answer: A. N33,333

Correct Answer: B. \(\frac{8}{4 - x^2}\)

Explanation

\(\frac{2}{2 + x} + \frac{2}{2 - x}\)

\(\frac{2(2 - x) + 2(2 + x)}{(2 + x)(2 - x)} = \frac{4 - 2x + 4 + 2x}{4 - 2x + 2x - x^2}\)

= \(\frac{8}{4 - x^2}\)

Correct Answer: D. gills

Explanation

Gills are specialized respiratory organs found in fish that allow them to extract oxygen from water. While a streamlined body, scales, and paired fins are all essential adaptations for fish to navigate and survive in water, none of them directly relate to the process of oxygen extraction and respiration like gills do. However, without gills, fish would not be able to respire efficiently underwater and would not survive in their aquatic habitats.

Correct Answer: C. The molecule are very fast apart & occupy all the space made available

Explanation

(a) (i) Polymerization is the combination of many molecules of the same kind to form a complex molecule Conc. H\(_2\)SO\(_4\) without gain or loss of material.

(b)(i) \(CH_3CH_2CH_2OH_{(aq)}\) ---> (CH_2CHCH_3\) + (\(H_2SO_4 + H_2O\)).

(ii) \(CH_3CH_2CH_2OH_{(aq)}\) + CHOOH --> \(CH_3CH_2CH_2OH_{(l)}\) + H\(_2\)O\(_{(l)}\)

(i) & (ii) are respectively dehydration and condensation type of reactions.

(c)(i) Carbon 40.O% = \(\frac{40}{12}\) = 3.33 moles ; Hydrogen 6.7% moles

\(\frac{6.7}{1} = 6.7\) moles

Oxygen 53.3% = \(\frac{53.3}{16}\) = 3.33 moles

Divide through by smaller number

i.e. C \(\frac{33}{3.33}\) : H \(\frac{6.7}{3.33}\) : O \(\frac{3.33}{3.33}\)

C = 1: H = 2.0: O = 1

Empirical formula = CH\(_2\)O(CH\(2\)O)x = 180

i.e. (30)x = 180

x = \(\frac{180}{30}\) = 6

Molecular formula = \(C_6H_{12}O_6\)

(ii) The intermolecular bonding in ethanoic acid is hydrogen bonding while the butane molecules are only aggregated by weak van der Waals.

Correct Answer: C. 17.5%

Explanation

\(\%Increase = \frac{Actual \hspace{1mm}increase}{initial \hspace{1mm}ratio}\times 100\%\)

Actual increase = 7; Initial ratio = 40

\(=\left(\frac{7}{40} \times 100\%\right)=\frac{35}{2}=17.5\%\)

Correct Answer: A. latter is owned solely by government while the former are not

Explanation

(a) Atmospheric resources:Are those elements such as wind, water, sunlight and gases which are of benefit to man, animals and plants

(b) Specific Examples

(1) Oxygen:

(i) Man breathes in oxygen

(ii) Oxygen combines with water vapour (oxidation) for chemical weathering

(iii) Supports animal life

(iv) Supports combustion

(v) For industrial purposes

(2) Carbon dioxide:

(i) Green plants take in carbon dioxide

(ii) Carbon dioxide and sunlight aid photosynthesis

(iii) Absorbs heat to control atmospheric temperature

(iv) Carbon dioxide combines with water to produce chemical weathering

(3) Nitrogen:

(i) Nitrogen in the atmosphere can be converted to nitrate in the soil

(ii) Combines with water to produce food for plants

(iii) May be used in electrical industries

(4) Water Vapour:

(i) Water vapour moderates atmospheric temperature

(ii) Important for rain formation

(iii) Resultant rain used by plants and animals effectively in the process of chemical weathering

(5) Sunlight:

(i) Provision of vitamin D

(ii) Important for drying

(iii) For photosynthesis

(iv) For solar energy

(6) Wind:

(i) For drying

(ii) For sporting (yatching)

(iii) For winnowing

(iv) For sailing

(7) Ozone: Protects the earth from ultra-violet rays of the sun.

Correct Answer: A) neutral

Correct Answer: C. ruku