Correct Answer: A. 3/16

Correct Answer: C. 13cm

Explanation

perimeter = 2(l + b) = 32

l + b = \(\frac{32}{2}\)

l + b = 16

b = 16 - 1.......(1)

Area = l + b = 39

lb = 39 .....(2)

put (1) into (2)

l(16 - 1) = 39

16l - l² = 39

l² = 13l - 3l + 39 = 0

l(l - 13) - 3(1 - 13) = 0

(l - 3)(l + 130 = 0

l - 3 = 0 or l - 13 = 0

l = 3cm or l = 13cm; The length in 13cm

Correct Answer: C. III

Correct Answer: D. Film, Aperture, Diaphragm

Explanation

(a) (i) Strong acid can ionize completely E.g. HCI\(_{(aq)}\) —> H\(^{+}_{(aq)}\) + CI\(^-_{(aq)}\) Concentrated acid means great amount of the acidic compound dissolved in little amount of water.

(ii) Amphoteric oxide is a metallic oxide which is both acidic and basic. E.g Al\(_2\)O\(_3\) + 6HCl —> 2AICl\(_3\) + 3H\(_2\)O\(_{(l)}\)

Al\(_2\)O\(_{3(5)}\) + 2NaO\(_{(aq)}\) + 3H\(_2\)O\(_1\) ---> 2NaAl(OH)\(_{4(aq)}\)

(b)(i) The manufacture of H\(_2\)SO\(_4\) by contact process sulphur(VI) oxide, the anhydride of H\(_2\)SO\(_4\) can be obtained by contact process which entails

The sulphur(VI) To dissolved in concentrated H\(_2\)SO\(_4\) to form, a fuming liquid called oleurn (H\(_2\)S\(_2\)O\(_{7(aq)}\))

H\(_2\)SO\(_{4(aq)}\) + SO\(_{3(g)}\) \(\to\) (H\(_2\)S\(_2\)O\(_{7(aq)}\)

The oleum is carefully diluted with correct amount of water to .give ordinary concentrated

H\(_2\)SO\(_{4}\).H\(_2\)S\(_2\)O\(_{7(aq)}\) + H\(_2\)O\(_{(l)}\) --> 2H\(_2\)SO\(_{4(aq)}\)

(ii) H\(_2\)SO\(_4\) as an oxidizing agent C\(_{(S)}\) + 2H\(_2\)SO\(_{4(aq)}\) -->2H\(_2\)O\(_{(l)}\) + 2SO\(_{2(g)}\) + CO\(_{2(s)}\) H\(_2\)SO\(_4\) as a dehydration agent H\(_2\)C\(_2\)O\(_{4(g)}\) + H\(_2\)SO\(_{4(l)}\) --> CO\(_{(g)}\) + CO\(_{2(g)}\) + (H\(_2\)O + H\(_2\)SO\(_{4(aq)}\)

(iii) It is commonly used in most industries.

Correct Answer: A. 35 mins

Explanation

Since 36km in 21 minutes

1km in \(\frac{21}{36}\)minutes

60km in \(\left(\frac{21}{36}\times 60\right)\)minutes = \(\frac{70}{2}\)min

= 35 mins

Correct Answer: D. 360

Explanation

(a) Processes of Soil Formation: Soil formation takes place over a long period of time and it involves the mixture of inorganic mineral water, organic water, liquid substances, gaseous substances, and living organisms. It begins with the production of inorganic mineral matter from parent materials and also involves accumulation or organic substances. Other processes include movement of weathered products in the form of clay particles, colloids or solutions and plant nutrients through soil profile as well as action of living organisms

(b) Importance of Soil;

(i) Food for micro-organisms

(ii) Medium for plant growth

(iii) Source of materials

(iv) Support for plants

(v) Habitat for macro and micro organisms

Correct Answer: B) forward baised

Correct Answer: A. time of delivery