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Form 4 Chemistry imtixaanka qaranka 2021 iyo jawaabihiisa

Imtixaanka qaranka Fasalka 4aad ee 2021 ee Form 4 Chemistry, su'aal su'aal. Ku gal adigoo waqti leh sida imtixaanka dhabta ah, kadibna arag jawaabta iyo sharaxa su'aal kasta.

45 su'aalood, 100 dhibcood
120 daqiiqo

Gal imtixaankan

120 daqiiqo, 100 dhibcood. Su'aalaha doorashada waa laguu saxayaa; jawaabaha qoraalka adiga ayaa ku saxaya qodobada sixitaanka.

Akoon bilaash ah ayaa loo baahan yahay si aad u bilowdo, si jawaabahaaga iyo natiijooyinkaaga loo kaydiyo.

Tilmaamaha ardayga

Answer all questions in the ANSWER BOOKLET. Time: 2 hours.

Section A (40 Marks, 2 marks each)

Choose the correct answer from the alternatives given in each question

1
Hydrocarbons are compounds that contain _____
- A.Carbon only
- B.Hydrogen only
- C.Oxygen
- D.Carbon and hydrogen
2 dhibcood
2
The simplest number of alkenes is known as _____
- A.Butane
- B.Ethane
- C.Ethene
- D.Propene
2 dhibcood
3
Which of the following groups has the most reactive non-metals _____
- A.Alkali metals
- B.alkaline metals
- C.halogens
- D.noble gas
2 dhibcood
4
The general formula of alkanes is _____
- A.CnH2n+2
- B.CnH2n
- C.CnH2n+1
- D.CnH2n-1
2 dhibcood
5
Phosphorous-32 has a half-life of 14.3 days. If a sample contains 8.0 mg of phosphoros-32 how many milligrams of phosphorous-32 remains after 42.9 days?
- A.4 mg
- B.6 mg
- C.2.5 mg
- D.1 mg
2 dhibcood
6
_____ is the simplest form of cyclo alkanes
- A.Cyclo butane
- B.cyclo pentane
- C.cyclo propane
- D.cyclo hexane
2 dhibcood
7
According to the general formula of alkenes (CnH2n), the molecular formula of butane is
- A.C4H10
- B.C4H8
- C.C4H12
- D.C4H6
2 dhibcood
8
The hydrophilic part of alcohol is called _____
- A.Alkyl part
- B.hydroxyl part
- C.hydrogen part
- D.carbon part
2 dhibcood
9
The structural formula of ketones is _____
- A.R-O-R
- B.R-C(=O)-R
- C.R-C(=O)-H
- D.R-C(=O)-O-R
2 dhibcood
10
If the number of protons and neutrons in a nucleus are 11, 12 respectively, the nuclear symbol would be:
- A.12/11 X (mass 12, atomic number 11)
- B.11/12 X (mass 11, atomic number 12)
- C.23/11 X (mass 23, atomic number 11)
- D.23/12 X (mass 23, atomic number 12)
2 dhibcood
11
The balance nuclear equation for (11/6 C) that produces a protons is _____
- A.11/6 C -> 1/1 e + 12/7 N
- B.11/6 C -> 0/1 e + 11/5 B
- C.11/6 C -> 0/1 e + 12/7 B
- D.11/6 C -> 0/1 e + 11/7 B
2 dhibcood
12
_____ is the substance that speed up the rate of reaction.
- A.Reactants
- B.Products
- C.Catalyst
- D.Activation energy
2 dhibcood
13
Identify the structure of 2-methyl pentane from the below structures.
- A.CH3-CH2-CH2-CH(CH3)-CH3
- B.CH3-CH(CH3)-CH3
- C.CH3-CH2-CH2-CH2-CH3
- D.CH3-C(CH3)2-CH3
2 dhibcood
14
Which of the following structures is saturated:
- A.CH=CH3
- B.CH=CH-CH3
- C.CH3-CH3
- D.CH3-CH2-C=CH
2 dhibcood
15
Which of the following figures indicates 2-methylphenol;
- A.Figure a (CH3 next to OH)
- B.Figure b
- C.Figure c (CH3 opposite OH)
- D.Figure d
2 dhibcood
16
The functional group that contains both aldehyde and ketone is known as _____
- A.Aldehyde group
- B.ketone group
- C.carbonyl group
- D.amino group
2 dhibcood
17
When one large nucleus splits into two smaller nucleus, this nuclear reaction is known as
- A.Fusion reaction
- B.fission reaction
- C.ionizing radiation
- D.alpha decay
2 dhibcood
18
Example of monosaccharide that contains five carbon (pentose) is _____
- A.Erythrose
- B.ribose
- C.galactose
- D.cellulose
2 dhibcood
19
Which of the following is homogeneous chemical equilibrium
- A.CO2(g) + C(s) <=> 2CO(g)
- B.CaCO3(s) <=> CaO + CO2
- C.P4(s) + 6Cl2(g) <=> 4PCl3
- D.N2 + O2 <=> 2NO(g)
2 dhibcood
20
Le Chatelier's principle states that if one or more factors disturb equilibrium, the position of equilibrium will shift in order to _____ the change.
- A.Oxidize
- B.increase
- C.induce
- D.reduce
2 dhibcood

Section B (10 Marks, 1 mark each)

Fill in the empty blank with suitable word from the box below

B1
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): The general structure of organic acid is _____
1 dhibcood
B2
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): The alcohol that contain two hydroxyl group is called _____ alcohol.
1 dhibcood
B3
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): Amino acids in the proteins are joined together by _____ bond
1 dhibcood
B4
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): The general formula of alkyne is _____
1 dhibcood
B5
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): The building unit of triglycerides is glycerol and _____ acids
1 dhibcood
B6
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): _____ equilibrium is a state in which the rates of the forward and reverse reactions are equal.
1 dhibcood
B7
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): The chemical constituents of the living system are called _____
1 dhibcood
B8
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): The radioactive decay which carry positive charge is known as _____ particles
1 dhibcood
B9
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): In equilibrium constant expression, if the value of Kc is greater than one (Kc > 1), this reaction is said to be _____ favoured.
1 dhibcood
B10
Fill in the empty blank with suitable word from the box (Isomers, Biomolecules, CnH2n-2, Dihydroxy, Peptide, R-COOH, Fatty, Chemical, Product, Alpha): _____ are molecules with the same molecular formula but different structural formula.
1 dhibcood

Section C (50 marks): Answer all questions in the section

C1a
a) What does IUPAC stands for? (2 mark)
2 dhibcood
C1b-a
b) Give IUPAC names to the following organic molecules (4 marks): a) CH3-CH(CH3)-CH2-CH3
1 dhibcood
C1b-b
b) Give IUPAC names to the following organic molecules (4 marks): b) CH3-CH=CH-CH(Br)-CH(CH3)-CH3
1 dhibcood
C1b-c
b) Give IUPAC names to the following organic molecules (4 marks): c) CH3-CH(Cl)-CH2-OH
1 dhibcood
C1b-d
b) Give IUPAC names to the following organic molecules (4 marks): d) CH3-CH2-C(=O)-H
1 dhibcood
C2
Phenols are hydroxyl derivatives of benzene that have aromas smell, state three uses of phenols. (3 Marks)
3 dhibcood
C3
Draw the possible structural formula for isomers of pentane using the following formula (2^(n-4) + 1). (3 marks)
3 dhibcood
C4a
Define: a. The term biochemistry? (2 mark)
2 dhibcood
C4b
b. Briefly explain the major types of biochemistry. (5 marks)
5 dhibcood
C5
Calculate the equilibrium constant (Kc), if the equilibrium concentrations are as follows: PCl5 (g) <=> PCl3 (g) + Cl2 (g). [PCl5] = 0.0096M, [PCl3] = 0.0247M, and [Cl2] = 0.0247M. (6 marks)
6 dhibcood
C6
The half-life of polonium-210 is 138.4 days, how many milligrams (mg) of polonium-210 remain after 415.2 day if you start with 2.0 mg of polonium-210? (5 marks)
5 dhibcood
C7
The rate of chemical reaction increases with increase in the presence of catalyst, explain. (5 marks)
5 dhibcood
C8
Distinguish between ionizing and non-ionizing radiation. (5 marks)
5 dhibcood
C9
A radioactive isotope of 38/19 K, emits a radioactive emission and changes into 36/18 Ar. Synthesize the balanced equation of this nuclear reaction (5 marks)
5 dhibcood
C10
Show the electron configuration of fluorine (9F) and chlorine (17Cl) (5 marks)
5 dhibcood

Imtixaanka waxaa diyaarisay Federal Ministry of Education, Culture and Higher Education (MoECHE), Somalia. Waxaa lagu wadaagay bilaash si ardaydu ugu diyaargaroobaan. Jawaabaha iyo sharaxyada waxaa qoray macallimiinta Sheerxirfad.

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