Correct Answer: B. has to forgo one thing in order to have another

Correct Answer: C. √6

Explanation

(a)A confederation is a loose political union, accommodating independent sovereign states, with the intention of coming together to co-operate in some vital areas, e. g . Communication, military, trade, etc., with each of them still retaining its sovereignty. The centre is weak, making the component states autonomous in the performance of political or other issues pertaining to them.

(b) Problems that are likely to arise in a Confederal State are:

(i)Weak Centre:The arrangement of a confederation makes for a weak centre that cannot effectively control the sovereign states that make up the union.

(ii)Problem of loyalty: Citizens will be more loyal to their state governments than the central body.

(iii)Secession: A confederal arrangement is fragile and can easily break up .

(iv) There is absence of national integration

(v)Problem of national unity: This is difficult to achieve because individual states still retain their separate identity.

(vi)The constitution: The constitution of a confederal state is assumed to be flexible because it can be amended without obtaining the overall support of the people that make up the confederation.

(vii)Global issues: A confederal state makes little or no impact on issues of global dimension.

(viii)It is Unpopular: Many sovereign states detest getting involved in such a political arrangement because of its unpopularity.

Correct Answer: C. penitence

Correct Answer: (c) Global system of Mobile communication

Correct Answer: B) nominal account and real account

Correct Answer: D. decline

Explanation

Wane; become weak. To decrease in strength, intensity.

Explanation

(a)(i) Contract process

(ii) Vanadium (v) oxide (V\(_2\)O\(_5\))

(iii) 2SO\(_{2(g)}\) + O\(_{2(g)}\) \(\rightleftharpoons\) 2SO\(_{3(g)}\)

SO\(_{3(g)}\) + H\(_2\)SO\(_4\)\(_{(/)}\) \(\to\) H\(_2\)S\(_2\)O\(_7\)

H\(_2\)S\(_2\)O\(_7\)\(_{(/)}\) + H\(_2\))\(_{(/)}\) \(\to\) 2H\(_2\)SO\(_{4(aq)}\)

(b)(i) Dehydration is the removeal of the element of water from a compound with change in the chemical composition of the compcu while drying is the removal of associated water from a substance without affecting it chemical composition.

(ii) Concentrated H\(_2\)SO\(_4\) reacts with ammonia to form ammonium tetraoxosulphate (VI)

(iii) CaO or silica gel.

(c)(i) I. lead chloride (PbCl\(_2\))

II. K\(_2\)CO\(_3\) or Na\(_2\)CO\(_3\)

III. ZnO or Al\(_2\)O\(_3\)

(ii) I - Reaction of an acid with base (neutralization reaction)

- Reactiction of an acid with a metal

- Reaction of an acid with trioxocarbonate (IV)

- Double decomposition

- Direct combination of its constituent element

- A metal with halogens

(iii) - Evaporation

- Crystallization

(d)(i) Gay lussac's Law of coming volumes states that when gases react, they do so in volumes which are in simple ratio to one another and to the volumes of the products if gaseous, provided that the temperature and pressure remains constant.

(ii) C\(_2\)H\(_{4(g)}\) + 3O\(_{2(g)}\) \(\to\) 2H\(_2\)O + 2Cl\(_{2(g)}\)

1 cm\(^3\) of ethene requires 3cm\(^3\) of oxygen

12.5cm\(^3\) of ethene will require 3 x 12.5cm\(^3\) of oxygen = 37.5cm\(^3\)

Correct Answer: D. Hydrogen

Explanation

The correct answer is hydrogen bonding, and each nucleotide attracts its pairing mate because they have corresponding number of hydrogen bonds. Adenine is attracted to thymine to create two hydrogen bonds, and cytosine is attracted to guanine to form three hydrogen bonds. While phosphodiester bonds are very important in creating the strand of DNA, they are not the bond that keeps the two strands in the double helix structure.

Correct Answer: C. Aeroplane