CONFIRM 2012 CHEMISTRY QUESTIONS AND ANSWERS

CHEMISTRY QUESTIONS

1.name three types of chemical reaction.

1b.explain any two with equation.

1c.three characteristics of catalyst.

1d.diffrenciate btw promoter and prohibitor,

2.state arrhenius theory,

2b.what is hydrolysis of salt,

2c,difference btw closed and open system,

2d.define buffer solution,

3.state le chatellier principle,

3b,state the effect of ,pressure,temp,catalyst on equilibrum,

3c,describe with the aid of diagram how hydrogen gas is used as reducing agent for named oxide,1,cuo,pbo,zno.

CHEMISTRY OBJECTIVE ANSWERS

1-10= dcdbeadbbe

11-20= cdcbaccecd

21-30= cceecbcbbc

31-40= cadabababa

41-50= eeebacabae

51-60= bbeacadcbb

CHEMISTRY THEORY ANSWERS

6ai. Polymerization is the joining together of similar molecule of unsaturated hydro carbon forming a single giant molecule called Polymer with or without d eliminations of small molecules.

6aii additional Polymerization condensation Polymerization

6aiii Rubber ii polythene

6bi] Heat and catalyst

ii] to ripen fruit

iii] to prepare polymer

6ci] primary

ii.] secondary

iii]. tertiary

1a.] Chain Reaction

ii. Reversible and irreversible reactions

iii]. endothermic and exothermic reactions

1aii catalyst is d ability of atoms of d same element to link dem selves while otcane no expresses d octane rating of petroleum

Solution to 1c.

Xcharatics of catalyst

i].artel the rate of chemical reaction

ii].a catalyst has no effect on the equilibrum of reversible reaction

iii].remain unchange at the end of reaction

4a i By diffusion

ii isotopy

iii radioactivity

iv sublimation

b i ethannol

ii soap

iii margarine

2a) Only the Arrhenius theory speaks about the need of water, according to Bronsted, acid base reactions can occur in gaseous state without water. (for example NH3+HCl).

3) Decomposition : A decomposition reaction is the opposite of a synthesis reaction - a complex moleculebreaks down to make simplerones. These reactions come inthe general form: AB --->A + B

One example of adecomposition reaction is the electrolysis of water to make oxygen and hydrogengas: 2 H 2 O --->2 H 2 + O 2

5b. ¡. Pollution:can be defined as the process of making the air impure due to contamination with harmful or prisonnus subtance

=pollutant:there are subtance that are used for polluting the air,eg oxides of carborn etc.

5b¡¡.Air pollutant oxide of sulpluer and nitrogen.

Water polution oilspills.

5c¡. Suphe soturated solutionin the one which continuns more of the solute than it can nomally hold at that temparature.

Q5. ¡ Allotropes of carbon=diamong =graphite

¡¡ Graphite conducts electricity

¡¡¡ this is becouse of the presence of mobite electrition in the erystall lattice