WAEC 2018 CHEMISTRY ALT A EXPO

MⓂr🅿: *CHEMISTRY DROPPED SOLUTIONS 

B)

i)        Concentration of A in mol dm-3

From the reaction equation

CA VA              =                      1                                  

CB VB                                      2

            CA        =                  CB VB

                                             2 VA

            CA        =               0.0975 x 25

                                                2 VA                            

                        =         P mol dm-3                   

                                                                        

Alternative Method:

Amount of acid used = 0.025 x 0.0975 = 0.00244 mol                                  

            From the equation of reaction:

                                    2 mol of B require 1 mol of A                                                

                                    0.00244 mol of B requires ½ x 0.00244 mol of A

                                                                                    = 0.00122 mol of A.   

                        i.e VA cm3 contain 0.00122 mol.

1000 cm3 contain 0.00122 x 1000/VA mol.

i.e. Conc of A = 1.22/VA = P mol dm-3

(ii)       Molar mass of H2Y

            Molar mass of H2Y =    6.22                                                               

                                                     P

                                    =          Q g mol-1

 Chemistry 3i).

Using BENEDICT'S REAGENT.

Step 1

Turn on your gas to medium heat and place your beaker filled with 100 mL of water on it. Bring it to a boil.

Step 2

  crush the solid sample into a powder using a mortar and pestle. Add water to the powder and pour it in the test tube.

Step 3

Add approximately 1 mL of Benedict’s solution to the test tube using a dropper. Slowly swirl the test tube counterclockwise to distribute the reagent evenly.

Step 4

Place your test tube into the beaker until you note a color change -- this process usually takes five minutes.

Step 5

Examine the color change, if it is present. Benedict’s reagent has a color change gradient from blue, meaning no simple sugars are present, to green, yellow, orange, red and brown. The color sequence indicates the increasing concentration of the simple sugar, with green being the lowest and brown being the highest.

B)

i)        Concentration of A in mol dm-3

From the reaction equation

CA VA              =                      1                                  

CB VB                                      2

            CA        =                  CB VB

                                             2 VA

            CA        =               0.0975 x 25

                                                2 VA                            

                        =         P mol dm-3                   

                                                                        

Alternative Method:

Amount of acid used = 0.025 x 0.0975 = 0.00244 mol                                  

            From the equation of reaction:

                                    2 mol of B require 1 mol of A                                                

                                    0.00244 mol of B requires ½ x 0.00244 mol of A

                                                                                    = 0.00122 mol of A.   

                        i.e VA cm3 contain 0.00122 mol.

1000 cm3 contain 0.00122 x 1000/VA mol.

i.e. Conc of A = 1.22/VA = P mol dm-3

(ii)       Molar mass of H2Y

            Molar mass of H2Y =    6.22                                                               

                                                     P

                                    =          Q g mol-1

[Chemistry 3i).

Using BENEDICT'S REAGENT.

Step 1

Turn on your gas to medium heat and place your beaker filled with 100 mL of water on it. Bring it to a boil.

Step 2

  crush the solid sample into a powder using a mortar and pestle. Add water to the powder and pour it in the test tube.

Step 3

Add approximately 1 mL of Benedict’s solution to the test tube using a dropper. Slowly swirl the test tube counterclockwise to distribute the reagent evenly.

Step 4

Place your test tube into the beaker until you note a color change -- this process usually takes five minutes.

Step 5

Examine the color change, if it is present. Benedict’s reagent has a color change gradient from blue, meaning no simple sugars are present, to green, yellow, orange, red and brown. The color sequence indicates the increasing concentration of the simple sugar, with green being the lowest and brown being the highest.

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WAEC 2018 GOVERNMENT THEORY & OBJ

GOVERNMENT THEORY

Govt-Obj
1-10: CADBCBBBDB
11-20: BDCCDABAAB
21-30: ACCAAACAAB
31-40: ADDCDDDDCC

41-50: ACAAABADBB

1b)

(i) Society is a largest human group.

(ii) It satisfies the needs of its members.

(iii)One of the characteristic of society is having sense of belonging and cooperation. It is more or less permanent association

(iv) It is abstract (Because social relationships can be felt and imagined and cannot be seen).

(v) Everyone in society is dependent upon every other member.

(vi) It should be organized i.e. will be having division of labor.

(vii) "There is consciousness of kind." Among the members of society.

(viii) It is always changing.

It has its own means to survive.

(ix) It is a self-sufficient social system.

(x)It lasts for a longer period of time than groups and communities.

(xi) One of the characteristic of society has its own culture.

3b) - Statutory age: An alien can become a citizen of another country if he has attained the required age as stipulated by the law of the country

- Good character : He/She must possess good character


7a) Protonationalism is generally referred to as traditional nationalists who were opposed to giving up their territories because they were denied respectable positions in their land or communities by reason of their race

7b)- Economic exploitation : There was economic exploitation of Nigerians by foreign firms

- Administrative post: Nigerians were not allowed to hold any administrative posts and the highest they could attain was that of Chief Clerk

- Lake of adequate educational facilities : The missionaries who were out to provide education did not achieve much due to financial problens

- Racial segregation : Discrimination against the natives was mostly witnessed in the 20th century in Nigeria.

2a)
Communalism is a political and economic arrangement with emphasis on collective,whereby the community agreed that they should co-operate and come together to harness their resources together for the good of everybody.

2b
1.Colective Ownership: There is collectivw ownership of the reso6
2.Community development:Opportunity for individuals to participate in community development is created
3.Self-government:Communal government is likened to self-government ,where public issues are raised and discussed openly.
4.Decision-making:Individual's Opportunity to contribute to the decision of decision making process of the community is enhanced
5.Landed Property:

3a) – By Birth : A person is a citizen by birth if either his parents, mother or father is a citizen of a country

– By naturalization : Somebody can become a citizen of a country where he lives through naturalization. This is possible if he can satisfy the constitutional requirements for naturalization

– Marriage or Registration : If a woman is married to a person of another nationality, she can acquire the citizenship of the husband’s country through registration

5(a) A constituency is a district or a geographical area created by an Electoral Commission for the election of one or more persons into the legislature.

(b)(i)community support;
      (ii)better knowledge of candidates;
      (iii)active participation;
       (iv)easy to operate;
        (v)less expensive;
        (vi)political stability;
        (vii)easy accountability to members of the constituency;
      (viii)emergence of the most popular candidate.

Choose any 5 above.
.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

6)- Appointment : The Emir appointment of officials e. g. Madawaki/Waziri/Galadima and Hakim to assist him in administering the emirate

– Social services : Provides social services for the people

– Communal work: The Emir organized his people for communal work e. g. roads and emir’s palace

– Defense: Organizes the people for defense of the emirate against external attacks

– Supreme leader: The emir was the Supreme leader of his subjects

7a) Protonationalism is generally referred to as traditional nationalists who were opposed to giving up their territories because they were denied respectable positions in their land or communities by reason of their race

7b)- Economic exploitation : There was economic exploitation of Nigerians by foreign firms

– Administrative post: Nigerians were not allowed to hold any administrative posts and the highest they could attain was that of Chief Clerk

– Lake of adequate educational facilities : The missionaries who were out to provide education did not achieve much due to financial problens

– Racial segregation : Discrimination against the natives was mostly witnessed in the 20th century in Nigeria.

*8*
*Answer any five(5)*

1. the President was the Chief Executive of the country who performed the day-today running of the country;

2. he inaugurated the National assembly at the beginning of each session;

3. he assented to bills duly passed by the National assembly into laws;
4. he appointed key officials of government;

5. he represented the country at international conferences like the UNO, AU, Commonwealth, ECOWAS, etc.;

6. he performed ceremonial functions;

7. he exercised prerogative of mercy i.e. he could pardon convicted persons or those found guilty of treason;

8. he signed treaties with other countries on behalf of the country;

9. he formulated policies for good governance;

*10.* he prepared and presented the annual

-Language barrier There are three languages that are used for communication within the ECOWAS bloc, that is English, French and Portuguese.

– Human Rights Abuses Another problem of the ECOWAS group is the penchant of the member states to abuse the human rights of their citizens. The human rights records of some member states is nothing to write home about.

– Financial problems The aims and objectives of the ECOWAS can only be achieved when the financial base of the community is solid. However, some member states are not able to honour their financial obligations to the community.

– Strong External Influence: Many of the member states of ECOWAS were former colonies of some former colonial powers. Countries such as Britain, France and Portugal ever had a colony
or two that now belong to the ECOWAS group.

– Widespread Poverty: Many of the member states of ECOWAS are among the poorest of the poor nations in the world. Many of their citizens earn less that a dollar a day.

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WAEC 2018 Geography practical

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(1d)- ground water resources

-Biological resources

2c)
-If well constructed it shows distribution and comparative densities

-It is easier to show variation in distribution of wide variety of commodities if it is presented using different colours.


4ai)
i)caves
ii)sinkholes
iii)skyline landscapes
4aii)
Drawing
4b)
i)Limestone are all used to neutralise excess acidity of soil in agriculture practice.
ii)Limestone is used as a building material.
iii)It is used in industries to purify iron in blast furnaces.
iv)It used in Glass making.

*5A*
Diagram loading

*5B*
*i.* The length of the minor arc of a great circle is taken as the distance between two points on a surface of a sphere in Riemannian geometry where such great circles are called Riemannia circles.
*ii.* These great circles are the geodesics of the sphere.
*Iiii* For most pairs of points on the surface of a sphere, there is a unique great circle through the two points.


5 c )
i ) it use in navigation and aviation .
ii) It Is Use To Know The shortest route between any two places is along the arc of the great circle which passes through them .
iii ) It Is Use In Ships crossing the vast oceans and aircrafts follow the Great circle route in order to save fuel and time .


8a)
i)Encroachment : More migration lead to
less availability of land which lead to higher economic value of land.
ii)Pollution: Explosive increase in the urban population without
corresponding expansion of civic facilities such as lack of adequate infrastructure for the disposal of waste results in waste clogging the
natural channels and storm water drains.
iii)Illegal mining activities: Illegal mining
for building material such as sand and quartzite both on the catchment and on the bed of the lake have extremely damaging impact on the water body.
iv)Interference in drainage system:
Drainage congestion caused by badly
planned construction of bridges , roads , railway tracts, hampers the
flow of water and the result is flood.

8b)
1. Flooding leads to loss of human life
2. Flooding leads to damage to property
3. It leads to destruction of crops
==============================
8c)
i)Improving Drainage
Improving water drainage helps control floods by
facilitating easy flow of excess water, especially in urban areas during flash floods.

ii)Building Dikes and Levees Dikes and levees are flood-control structures built to fight
river flooding and water surges.

iii)Building Canals
Canals are artificial water channels that can be crucial to flood prevention. Canals facilitate control of water levels passing through, and form linear reservoirs and water
locks.

iv)Harvesting Rain Water
Harvesting rainwater involves collecting and storing rainwater and can not only prevent floods, it can also curb urban water scarcity.

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Verified physics theory & obj

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🔰💶🔰💶

PHYSICS OBJECTIVES ANSWERS👇👇:

1-10: CAABACBADB
11-20:ACCCDABDCC
21-30:DBADCABCAB
31-40:CCBBCCBABD 
41-50:BDCDBABBDC

Please don't rush use our own obj

Stay calm and relax 

Solving ✍✍✍

PHYSICS OBJECTIVES QUESTIONS

 1a*

Strain is
force (a part of one’s body or oneself) to make an unusually great effort.

2 )
i ) quantity of charge
ii) nature of element
iii ) Time

2biThe boiling point of a liquid Is the point at which The vapour pressure is equal To atmospheric pressure

3)
-Diamagnetic material
-Paramagnetic material
-Ferromagnetic material

4a)An intrinsic semiconductor, also called an undoped semiconductoror i-type semiconductor, is a pure semiconductor without any significant dopant species present. The number of charge carriers is therefore determined by the properties of the material itself instead of the amount of impurities.

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

4b)
i)Rockets are used for space travel
ii)military uses, 
iii)launching satellites into space

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

*5)*
Range = u²Sin2tita/g
At maximum range 
Sin2tita = 1
2tita =sin^-1(1)
2tita = 90dgrees 
Tita = 90/2 = 45degree

Maximum height reached = u²sin²tita/2g
=u²(sin45)²/2g
=200²(sin45)²/2(10)
=40000(1/√2)2/20
=40000(1/2)/20
=20000/20
=1000metres.

6)
Given constant = 2.9×10^-3mk
Temperature = 57degreeC = (57+273)k = 330k
Using landamaxT = constant
landamaxT330 = 2.9×10^-3
landamax = 2.9×10^-3/330
landamax = 8.788×10^-6m
The speed of electromagnetic wave, v = 3×10^8m/s
Using V = f landa
f = v/landa
=3×10^8/8.788×10^-6
=3.4×10^13Hz

7(a). LASER stands for Light Amplification by Stimulated Emission of Radiation.

(b). A laser is a device that emits a beam of coherent light through an optical amplification process.

9a(i) 
i. Nature of the Substance 
ii.Medium of transmission 

9a(ii)
i.State or phase of the substance (i.e Solid, Liquid or gas). 
ii.Temperature of the medium 

9b) 
i. Temperature 
ii. Specific hear capicity kf the Body

9c) 
The statement means that the amount of hear energy required to change 1kg of liquid mercury to gaseous mercury without chang3 in temperature is 2.72*10^5Kg^-1

9d(i)
PleasenNote (π) means Change in temperature Q

Q=MCπQ

V^2/R * t=MCπQ

(220)^2*4*60/35=M*4200*(100-28)

33,885.7=302400m

M=33,885.7/302400

M=1.098kg

9d(ii) 
V^2/R *t=MLv

(220)^2 *5 *60/35=0.3*Lv

414857.14=0.3Lv

Lv=414857.14/0.3

Lv=1382857.13Jkg^-1

*10a*
the process by which a beam of light or other system of waves is spread out as a result of passing through a narrow aperture or across an edge, typically accompanied by interference between the wave forms produced.

10b
Critical angle: This is the angle of incidence in the denser medium when the angle of refraction in the less dense medium is 90°

*10bi*
the angle of incidence beyond which rays of light passing through a denser medium to the surface of a less dense medium are no longer refracted but totally reflected.

12a)

binding energy is the minimum energy that would be required to disassemble the nucleus of an atom into its component parts. These component parts are neutrons and protons, which are collectively called nucleons

12b)* They have short wire length and high frequency.

-They are highly penetrating

-They travel in straight line

-They don’t require material medium for their propagation

(12a) This is defined as the amount of energy that must be supplied to a nucleus to completely separate it's nuclear particles (nucleons)

(12b) 
(i) They have short wavelength and high frequency. 
(ii) They are highly penetrating. 
(iii) They travel in straight lines. 
(iv) They don't require material medium for their propagation.

(12c) 
-It is used in production of electricity. 
-It is used to study and detect charges in genetic engineering. 
-It is used in agriculture. 
-It is used in treatment of cancer. 

(12di)
E = hf-hfo
but f = v/landa
E= v/landa.h - wo
Where wo = hfo = work function 
f= frequency 
landa = wavelength 
Hence 
hf = hfo - E
f = hfo - E/h
f = wo - E/h
Recall; that v = f landa
Therefore f = v/landa = 3×10^8/4.5×10-7
=3/4.5 × 10^8+7
=6.6×10^14Hz
f = 6.6×10^14Hz

(12dii) 
E = hf
=6.6×10^-34 × 6.6×10^14Hz
=43.56×10^-20J

(12diii) 
Energy of the photoelectron E = hf - vo
=Energy of incident electron - work function 
=4.356×10^-19J - 3.0×10^-19J

=1.356×10^-19J

*SNT*

NIGERIA PH

NIGERIA PHYSICS THEORY

G

HANA AND SIERRA LEONE PHYSICS THEORY

SHINING STARS TEAM

Ghana and Sierra Leone

*3a*

Snell’s Law states that the ratio of the angle of incidence to the angle of refraction of a wave as it travels through a boundary between two media is a constant termed the refractive index. The value of this constant is equal to the ratio of speeds before and after it crosses the boundary.

Q4a

Self Inductance
Definition: Self-inductance or in other words inductance of the coil is defined as the property of the coil due to which it opposes the change of current flowing through it. Inductance is attained by a coil due to the self-induced emf produced in the coil itself by changing the current flowing through it.

5a)
i. Stress: is the proportional to strain provided elastic limit is not exceeded,(F/A).

ii. Strain is define as the ratio of the extension to original length,(e/l) it has no unit.

iii. Young’s Modulus is the Constant of Proportionality in Hooke’s Law..
Young Modulus= Stress/Stain

*5ai*
STRESS is
(force) per unit area that tends to deform the body on which it acts

*5aii*
Strain is
force (a part of one’s body or oneself) to make an unusually great effort.

SEE ALSO:   Waec 2018 English Obj And Theory Answers – May/June Expo

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