NABTEB CHEMISTRY ANSWER 2019

Chem-Obj

1BCDCDCCDDA

11CDBDBDDCAB

21DBDBACDCBD

31BDCCACABAB

41BBCDCBABBC

===================================

 

(1ai)

CH3COOH + C2H5OH –> CH3COOC2H4 +H2O

(ethylethanoate)

(1aii) Amino acids

(1aiii) -COOH and -NH

(1bi)

(pick 3)

– They have the same general formula

– They have the same general method of preparation

– They have the same chemical properties

– Successive members are differ by CH2

– The physical property increase steadily with increase in relative molecular mass

(1bii)

(pick 1)

– Methane -CH4

– Ethane – C2H6

– Propane – C3H8

– Butane – C4H10

(1biii)

Carbon. | Hydrogen

Mass – 92.3 | 7.7

Mole – 92.3/12 | 7.7/1

7.69/7.69 | 7.7/7.69

1 | 1

Empirical formula = CH

(1biv)

n(CH)=78

n(12+1)=78

13n=78

n=78/13

n=6

:. The empirical formula =C6H6

(1av)

Benzene C6H6

H

|

C

//

H-C C-H

| ||

H-C C-H

/

C

|

H

Cyclohexane

H

|

C

/

H-C C-H

| |

H-C C-H

/

C

|

H

C2H5-C=_(use triple bond)C-C2H5

1,2,- diethylethyne

(1c)

(pick 2)

– It is used for boring holes into rocks

– It is used for cutting glass

– It is used as jewelry

===================================

(2ai)

Le chatelier principle states that if a system is at equilibrium and one part of the system is altered, the equilibrium will shift so as to remove the alterations

(2aii)

N2(g) + 3H2(g) —> 2NH3 ?H

The conditions that favour a high yield of ammonia are:

– Increasing the concentration of N2 and H2

– Decreasing the temperature of the system

– Increasing the pressure of the system

(2biii)

(i) A thick white smoke of ammonium chloride is formed

(ii) An insoluble pale blue precipitate of copper (II) hydroxide is formed

(2bi)

1s^2

(2bii)

(pick 2)

– It does not support combustions

– It readily liquefies and solidifies on cooling

– It has the ability to sublime at lower temperature ( -780degree)

(2biii)

H

|

C

//

H-C C-H

| ||

H-C C-H

/

C

|

H

(2ci)

Additional polymerization is the type of polymerization which occur when polymer is formed by the sequential addition of monomer units repeatedly without the co-generation of other product.

(2cii)

Unsaturated Hydrocarbon

(2ciii)

(pick 2)

– Length of the chain of the polymer

– Attractive force between polymer chain

– Branch chain of the polymer

– Cross linking of the polymer

(2d)

CLICK HERE FOR THE IMAGE

===================================

(3ai)

(pick 2)

– Temperature

– Nature of the substance

– Concentration of the reactant

– Surface area of reactant

(3aiv)

600cm^3

(3av)

18cm^3

(3avi)

50cm^3

(3bi)

TABULATE

– ELECTROVALENT COMPOUND – (pick 3)

– They consist of ions

– They have the ability to conduct electricity

– They have high melting and boiling

– They are soluble in water and insoluble in organic solvent

– COVALENT COMPOUND – (pick 3)

– They consist of molecules

– They do not conduct electricity

– They have low melting and boiling point

– They are insoluble in water and soluble in organic solvent

(3bii)

(pick 2)

– They are good conductors of electricity

– They are lustrous

– They are solid at room temperature except mercury

– They are malleable

– They are ductile

– They have high melting points

(3biii)

Nuclear fission

(3biv)

x is beta particle

(3bv)

(pick 2)

– Scintillation Counter

– Diffusion cloud chamber

– Geiger – Muller counter

(3ci)

Downward delivery

(3cii)

(pick 2)

– Ammonia gas

– Hydrochloride gas

– Sulphur (IV) oxide gas

===================================

(4ai)

Allotropy is the existence of a substance in various forms with the same physical state

(4aii)

Rhombic Sulphur

(4aiii)

(pick 1)

– Coal

– Petrol

– Diesel

(4aiv)

It has sharp and suffocating odour

(4bi)

Acid salt are salt that contain a positive metallic or ammonium ion with a negative acid radical ion.

(pick 2)

– NaHSO4

– CaHPO4

– NH4HCO3

– CuHCO3

– MgHSO4

(4bii)

The acid attacks and stains Rutter and cork

(4ci)

CLICK HERE FOR THE IMAGE

(4cii)

At cathode

Calcium ions receive two elections

Ca^2+ + 2e^- —–> Ca(s)

At the anode

The chlorine ions give up an electron each to become atomic chlorine

Cl^- ——> Cl + e^-

(4ciii)

It is used to lower the temperature or melting point from 850degree(c) to 650degree(c)

===================================

(5ai)

Homologous series is a series of compound bond together with a general formula and in which each member differs from the next member by CH2

(5aii)

– Alkanoic acid

– Aminoalkanoic acid

(5aiii)

– Alkanoic acid (pick 1)

* Propanoic acid

* Ethanoic acid

* Butanoic acid

– Aminoalkanoic acid (pick 1)

* Aminoethanoic acid

* Aminoethanoic acid

* Aminobutanoic acid

(5aiv)

(pick 2)

– Natural gas

– Petrol

– Kerosene

– Diesel oil

– Lubricating oil

– Bitumen

(5b)

(i) CaO

(ii) Ca(OH)2

(iii) CaCO3

(iv) CaO

(v) NaOH

(5c)

(i) CuSO2.2H2O = Copper sulphate (vi) dihydrate

(ii) NaHSO4 = Sodium hydrogen sulphate (vi)

(iii) ZnCO3 = Zinc trioxocarbonate (iv)

(5di)

1,2-dichloroethene

Cl Cl

| |

H-C = C-H

(5dii)

Methylethanoate

H O-CH3

| /

H-C-C

|

H O

===================================

COMPLETED!.

 

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Posted by admin on 20th May 2019.

Tags: how can I get early weac and jamb answers, How do I know the best site I can subscribe or pay for jamb runs, pls show me the best site for jamb runs, were can I get free weac answer, what is the fastest exam runs site

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