MrEDUCATION:
Quick Revision Questions in CHEMISTRY.

To be answered in 20minutes !

The correct answers will be posted with EXPLANATIONS in 24 hours!


1 : The knowledge of half-life can be used to ___
A ) create an element.
B ) detect an element.
C ) split an element.
D ) irradiate an element.


2 : Sieving is a technique used to separate mixtures containing solid particles of _______
A ) small sizes.
B ) large sizes.
C ) different sizes.
D ) the same size.


3 : A mixture of iodine and sulphur crystals can be separated by treatment with _________
A ) water to filter off sulphur.
B ) carbon (IV) sulphide to filter off iodine.
C ) ethanoic acid to filter of sulphur.
D ) methanol to filter off iodine.


4 : The ratio of the initial to the final pressure of a given mass of gas is 1 : 1.5 . Calculate the final volume of the gas if the initial volume was 300cm³ at the same temperature _______
A ) 750cm³
B ) 120cm³
C ) 200cm³
D ) 450cm³


5 : The fundamental difference between the three states of matter is the ________
A ) shape of their particles.
B ) number of particles in each state.
C ) shape of the container they occupy.
D ) degree of movement of their particles.


6 : 50cm³ of carbon (II) oxide was exploded with 150cm³ of air containing 20% of Oxygen by volume. Which of these reactants was in excess? ________
A ) carbon (II) oxide.
B ) carbon (IV) oxide.
C ) Oxygen.
D ) Nitrogen.


7 : The distance between the nuclei of chlorine atoms in a chlorine is 0.194mm. The atomic radius of chlorine atom is ? ________
A ) 0.097mm
B ) 0.194mm
C ) 0.388mm
D ) 2.388mm


8 : The pOH of a solution of 0.25 mol per dm³ of hydrochloric acid is? _________
A ) 12.40
B ) 13.40
C ) 14.40
D ) 14.60


9 : ½Zn²⁺_aq + e- ------> ½Zn _(s)

In the reaction above, calculate the quantity of electricity required to discharge Zinc. ______
A ) 0.965 x 10⁴ C
B ) 4.820 x 10⁴ C
C ) 9.650 x 10⁴ C
D ) 48.200 x 10⁴ C
[F = 96500 Coulomb per mol]


10 : 0.46g of ethanol when burned raised the temperature of 50g of water by 14.3K. Calculate the heat of combustion of ethanol. _______
A ) +3000kJ per mol
B ) +300kJ per mol
C ) -300kJ per mol
D ) -3000kJ per mol
[C = 12, O = 16, H = 1, Specific heat capacity of water = 4.2 Joule per gram per Kelvin]

dolapo74:
I suggest that you go to cbt center.
they should know better.

Quick Revision Questions in CHEMISTRY. 

To be answered in 20minutes !

I will post the CORRECT ANSWERS with EXPLANATIONS to the questions in 24 hours!



1 : The knowledge of half-life can be used to ___
A ) create an element.
B ) detect an element.
C ) split an element.
D ) irradiate an element.

The Answer is B  because half-life of a radioactive isotope is the time taken for a half of the original quantity to change or decay.It is used by geologists in dating geological remains .For instance; the quantities of uranium -238 in rocks are used to determine their ages. Similarly, in archaeological dating, the half-life of carbon-14(an isotope of carbon-12) enables the age of the remains of an organism such as a plant, to be deduced by comparing carbon-14 content of a dead plant with that of a similar living plant.


2 : Sieving is a technique used to separate mixtures containing solid particles of _______
A ) small sizes.
B ) large sizes.
C ) different sizes.
D ) the same size.

The Answer is C  because sieving is a separation technique based on the differences in the particle sizes of the components of the mixture. Examples are: soil sample, and iron filings of various sizes.


3 : A mixture of iodine and sulphur crystals can be separated by treatment with _________
A ) water to filter off sulphur.
B ) carbon (IV) sulphide to filter off iodine.
C ) ethanoic acid to filter of sulphur.
D ) methanol to filter off iodine.

The Answer is B  because sulphur is insoluble in water, but soluble in carbon (IV) sulphide.


4 : The ratio of the initial to the final pressure of a given mass of gas is 1 : 1.5 . Calculate the final volume of the gas if the initial volume was 300cm³ at the same temperature _______
A ) 750cm³
B ) 120cm³
C ) 200cm³
D ) 450cm³

The Answer is C because,using Boyle's law, P₁ x V₁ = P₂ x V₂ , where P₁ = 1, P₂ = 1.5, V₁ = 300cm³, but V₂ =?...Making V₂ the subject of the formula, V₂ = P₁ x V₁ /P₂ = 1 x 300/1.5 = 200cm³.
 

5 : The fundamental difference between the three states of matter is the ________
A ) shape of their particles.
B ) number of particles in each state.
C ) shape of the container they occupy.
D ) degree of movement of their particles.

The Answer is D because the forces of attraction or cohesion between the particles of solid matter are stronger than that in the liquid matter which is in turn stronger than the cohesive forces of the gaseous matter. This implies that gaseous particles can move faster and further than liquid particles which can in turn move faster and furter than solid particles .This accounts for the fundamental disparity between the three states of matter.


6 : 50cm³ of carbon (II) oxide was exploded with 150cm³ of air containing 20% of Oxygen by volume. Which of these reactants was in excess? ________
A ) carbon (II) oxide.
B ) carbon (IV) oxide.
C ) Oxygen.
D ) Nitrogen.

The Answer is C because from the equation of the reaction:
2CO + O₂ -------> 2CO₂
and applying Gay-Lussac's Law of Combining Volumes,  2cm³ of CO reacted with 1cm³ of O₂ to give 2cm³ of CO₂ .This suggests that 50cm³ of CO should react with 25cm³ of O₂ to give 50cm³ of CO₂ .Volume of Oxygen given is 20% of 150cm³ of air which is equal to 30cm³.This volume of oxygen (30cm³) is more than the conventional or espected volume of oxygen (25cm³) needed to react with 50cm³ of CO;Thus,Oxygen is in excess by 5cm³.
 

7 : The distance between the nuclei of chlorine atoms in a chlorine is 0.194mm. The atomic radius of chlorine atom is ? ________
A ) 0.097mm
B ) 0.194mm
C ) 0.388mm
D ) 2.388mm

The Answer is A because radius of an atom is the distance between the centre of the nucleus and the outermost electronic shell. In an atom, the orbiting electrons may be best represented by an electron cloud. Since the electron cloud of an atom has no definite limit, the size of an atom cannot be defined easily. However, using X-ray and electron diffraction techniques,it is possible to determine the distance between covalently bonded atoms. Generally, the atomic radius is taken to be one-half the distance of closest approach between the nuclei of atoms in the elemental substance. So, in this case, the radius of a chlorine atom is 0.194mm/2 =0.097mm.


8 : The pOH of a solution of 0.25 mol per dm³ of hydrochloric acid is? _________
A ) 12.40
B ) 13.40
C ) 14.40
D ) 14.60

The Answer is B because according to Sørensen Peder Lauritz Sørensen in 1909, the pH of a solution is the negative logarithm of the hydrogen ion concentration to the base 10. That is : pH= -Log[H⁺] . The hydrogen ion concentration in hydrochloric acid has been given to be 0.25mole per dm³ . Therefore, pH= -Log[0.25] = 0.6021.But,
pOH = 14 - pH.  Therefore, pOH = 14th - 0.6021 = 13.3979 ≈ 13.4 .


9 : ½Zn²⁺_(aq) + e-  ------> ½Zn_(s)
In the reaction above, calculate the quantity of electricity required to discharge Zinc. ______
A ) 0.965 x 10⁴ C
B ) 4.820 x 10⁴ C
C ) 9.650 x 10⁴ C
D ) 48.200 x 10⁴ C
[F = 96500 Coulomb per mol]

The Answer is C because the equation for the discharge of one mole of Zinc is : Zn²⁺_(aq) +  2e-  ------>  Zn_(s) . From the equation of the reaction, 2Faradays of electricity are required to discharge 1mole of Zinc. This means that 1mole of Zinc requires 2 x 96500 Coulombs of electricity to be discharged. Therefore, ½ mole of Zink will reuqire ½ x 2 x 96500 = 96500 Coulombs = 9.650 x 10⁴ C


10 : 0.46g of ethanol when burned raised the temperature of 50g of water by 14.3K. Calculate the heat of combustion of ethanol. _______
A ) +3000kJ per mol
B ) +300kJ per mol
C ) -300kJ per mol
D ) -3000kJ per mol
[C = 12, O = 16, H = 1, Specific heat capacity of water = 4.2 Joule per gram per Kelvin]

The answer is C because, calculating the heat accumulated by the 50g of water, using, H = MC∅ = 50 x 4.2 x 14.3 = 3003Joules of heat. This means that 0.46g of ethanol produced 3003 Joules of heat. Therefore 46g of ethanol will produce 46 x 3003/0.46 = 300300J ≈ -300kJ
(because the process is exothermic)

DrOptimistic:



I have gone to the cbt centre. They said I can't access my jamb profile through my phone now that I will be able to access it during reprinting of exam slip.
Could this be true ??
Does it occur to other candidates too??

MrEDUCATION:
The CORRECT ANSWERS with their EXPLANATIONS.

afoobabs:


No.
after registration candidate can login anytime, anyday and anywhere

if you are in whatsapp kindly drop ur number may be i can help you out

below is the screen shot of candidate's profile as at today 27th February, 2019

afoobabs:


No.
after registration candidate can login anytime, anyday and anywhere

if you are in whatsapp kindly drop ur number may be i can help you out

below is the screen shot of candidate's profile as at today 27th February, 2019

DrOptimistic:




If you have seen this notify and make sure you edit your post before quoting.
Thanks in anticipation

Complexx:
Phy,chem ,math,eng, pls is this correct for ui jamb sub comb for mathematics education

DrOptimistic:



But the screenshot is showing 2018 instead of 2019

afoobabs:

clear the number now

afoobabs:

that shouldnt be candidate's head
it same for every one

DrOptimistic:



AADCDBCBBCDC

MrEDUCATION:
Quick Revision Tips in BIOLOGY



# The smallest,softest and lightest bones in the human body are the ear ossicles which include; malleus or hammer, incus or anvil and stapes or stirrup.


# The TOTAL number of Bones in an adult human is 206 while that in a new born baby is around 305 bones


# The Number of Muscles in man is approximately 639 to 640.


# Human beings have two(2) Kidneys


# There are 20 primary, 'baby' or 'milk' teeth and 32 permanent or 'adult' teeth in Humans.



# A typical human rib cage consist of 24 Ribs in 12 pairs.


# The heart of a fish have two chambers; one atrium and one ventricle.There are three chambers in the heart of amphibians; two atria and one ventricle. In Reptiles,the ventricles have partially developed partition, while mammals and birds have four chambers in their heart; two atria and two ventricles.


# The Normal blood pressure in man is 120/80mmHg.Hypertension occures when the blood pressure is 130/80mmHg or higher.


# The human blood is normally slightly basic. The usual pH of blood is 7.40 .



# The CERVICAL VERTEBRAE are 7 in number, the THORACIC VERTEBRAE are 12 in number, the LUMBAR VERTEBRAE are 5 in number, the SACRAL VERTEBRAE are 5 in number and the CAUDAL VERTEBRAE are 4 in number making the total number of vertebrae in the Spinal column to be 33 in number.


# In the human skull, the facial skeleton consist of 14 bones in the face.


# The Human Skull is generally considered to consist of 22 Bones,eight cranial bones and fourteen facial skeleton bones.


# There are usually 26 bones in the chest of man.

# The longest bone in the human body is the femur.


#The largest artery is the Aorta and the largest vein is the Inferior Vena Cava.


# The largest internal organ is the liver.It is also the heaviest organ, with an average of 1.6 kilograms (3.5 pounds).


# The largest external organ, which is also the largest organ in general, is the skin.


# The Largest gland in the human body is Liver.


# The biggest cell in humans is the egg cell or Ovum in women while the smallest cell is the sperm cell in men.


# The average length of the Small Intestine is 6metres while the average length of Large Intestine is 1.5metres .


# The average weight of a new Born baby is 2.6kg.


# The normal body temperature of man is 37 C° (98.6 F°).


# The average blood volume in humans is 4 to 5 liters.


# The Life Span of Red Blood Cells is approximately 120 days.


# The Life Span of White Blood Cells ranges from 13 to 20 days.


# The average length of human gestation(Pregnancy Period) is 280 days (40 weeks).That of goats is 150days(5weeks) and that of cattle is 283days.


# The number of Bones in Each wrist is 8.


# The Largest Endocrine gland in man is the Thyroid gland.


# The Largest Lymphatic Organ in the body is the Spleen.


# Cerebrum is the largest part of the brain,making up about two-thirds of its mass.


# The Largest and Strongest Bone in the human body is Femur.


# Each cell in humans normally contains 23 pairs of Chromosomes which gives a total of 46 Chromosomes.


# The Universal Donor is Blood Group O.


# The Universal Recipient is Blood Group AB.


# The Largest White Blood Cell is the Monocyte while the Smallest White blood cell is the Lymphocyte.


# Increase in Red Blood Cell count called Polycythemia.


# Spleen is the Blood Bank in the Body.


# Red Blood Cell is produced in the Bone Marrow.


# Blood is the river of life.


# Normal Blood Cholesterol level 200milligrams per decilitre.


# The fluid part of the Blood is the Plasma.


# The Normal Blood Sugar Level is 100mg/dl.



To Be Continued...

Itzneowizy:
Haven't gotten time to look at the rest..but i doubt ur number one ansa

DrOptimistic:



What do you think is the correct answer?


Try and answer the questions

MrEDUCATION:
300+ RECORD BREAKERS in JAMB Series.

Quick hot Revision Qestions in BIOLOGY.

Ten questions to be answered in 15 minutes!

The CORRECT ANSWERS with their EXPLANATIONS will be released in 24 hours!


1 : The smallest living organisms which share the characteristics of both living and non living matter are ________?
A ) Bacteria.
B ) Fungi.
C ) Virus.
D ) Protozoa.


2 : The cell of an onion bulb can be differentiated from a cheek cell by the presence of _______?
A ) Plasmalemma.
B ) Chloroplast.
C ) Cell wall.
D ) Nucleus.


3 : In a cell, the genes are carried by _______?
A ) Nuclear membrane.
B ) Lysosomes.
C ) Chromatin threads.
D ) Mitochondria.


4 : The membrane surrounding the vacuole in a plant cell is called the _____?
A ) Plasmalemma.
B ) Tonoplast.
C ) Nuclear membrane.
D ) Endoplasmic reticulum.


5 : A group of similar cells performing the same function is _______?
A ) an organ.
B ) a tissue.
C ) a system .
D ) an organelle.
E ) an enzyme.


6 : An amoeba and an unlaid chicken egg are _______?
A ) Animal tissues.
B ) Organelles.
C ) Single cells.
D ) Organisms.


7 : The rods in the retina of the eye are examples of _______?
A ) Organs.
B ) Cells.
C ) Tissues.
D ) Systems.


8 : What is the level of organisation of an onion bulb _______?
A ) Tissue.
B ) Organ.
C ) Systemic.
D ) Organism.


9 : Which of the following does a virus have in common with animal cells____?
A ) Nucleus.
B ) DNA.
C ) Glycogen.
D ) Cytoplasm.


10 : The pioneer organisms in an ecological succession are usually the ______?
A ) Lichens.
B ) Algae.
C ) Ferns.
D ) Mosses.

MrEDUCATION:
300+ RECORD BREAKERS in JAMB Series.

Quick hot Revision Qestions in BIOLOGY.

Ten questions to be answered in 15 minutes!

The CORRECT ANSWERS with their EXPLANATIONS will be released in 24 hours!


1 : The smallest living organisms which share the characteristics of both living and non living matter are ________?
A ) Bacteria.
B ) Fungi.
C ) Virus.
D ) Protozoa.


2 : The cell of an onion bulb can be differentiated from a cheek cell by the presence of _______?
A ) Plasmalemma.
B ) Chloroplast.
C ) Cell wall.
D ) Nucleus.


3 : In a cell, the genes are carried by _______?
A ) Nuclear membrane.
B ) Lysosomes.
C ) Chromatin threads.
D ) Mitochondria.


4 : The membrane surrounding the vacuole in a plant cell is called the _____?
A ) Plasmalemma.
B ) Tonoplast.
C ) Nuclear membrane.
D ) Endoplasmic reticulum.


5 : A group of similar cells performing the same function is _______?
A ) an organ.
B ) a tissue.
C ) a system .
D ) an organelle.
E ) an enzyme.


6 : An amoeba and an unlaid chicken egg are _______?
A ) Animal tissues.
B ) Organelles.
C ) Single cells.
D ) Organisms.


7 : The rods in the retina of the eye are examples of _______?
A ) Organs.
B ) Cells.
C ) Tissues.
D ) Systems.


8 : What is the level of organisation of an onion bulb _______?
A ) Tissue.
B ) Organ.
C ) Systemic.
D ) Organism.


9 : Which of the following does a virus have in common with animal cells____?
A ) Nucleus.
B ) DNA.
C ) Glycogen.
D ) Cytoplasm.


10 : The pioneer organisms in an ecological succession are usually the ______?
A ) Lichens.
B ) Algae.
C ) Ferns.
D ) Mosses.

MrEDUCATION:
300+ RECORD BREAKERS in JAMB Series.

Quick hot Revision Qestions in BIOLOGY.

Ten questions to be answered in 15 minutes!

The CORRECT ANSWERS with their EXPLANATIONS will be released in 24 hours!


1 : The smallest living organisms which share the characteristics of both living and non living matter are ________?
A ) Bacteria.
B ) Fungi.
C ) Virus.
D ) Protozoa.


2 : The cell of an onion bulb can be differentiated from a cheek cell by the presence of _______?
A ) Plasmalemma.
B ) Chloroplast.
C ) Cell wall.
D ) Nucleus.


3 : In a cell, the genes are carried by _______?
A ) Nuclear membrane.
B ) Lysosomes.
C ) Chromatin threads.
D ) Mitochondria.


4 : The membrane surrounding the vacuole in a plant cell is called the _____?
A ) Plasmalemma.
B ) Tonoplast.
C ) Nuclear membrane.
D ) Endoplasmic reticulum.


5 : A group of similar cells performing the same function is _______?
A ) an organ.
B ) a tissue.
C ) a system .
D ) an organelle.
E ) an enzyme.


6 : An amoeba and an unlaid chicken egg are _______?
A ) Animal tissues.
B ) Organelles.
C ) Single cells.
D ) Organisms.


7 : The rods in the retina of the eye are examples of _______?
A ) Organs.
B ) Cells.
C ) Tissues.
D ) Systems.


8 : What is the level of organisation of an onion bulb _______?
A ) Tissue.
B ) Organ.
C ) Systemic.
D ) Organism.


9 : Which of the following does a virus have in common with animal cells____?
A ) Nucleus.
B ) DNA.
C ) Glycogen.
D ) Cytoplasm.


10 : The pioneer organisms in an ecological succession are usually the ______?
A ) Lichens.
B ) Algae.
C ) Ferns.
D ) Mosses.

300+ RECORD BREAKERS in JAMB Series.

Quick hot Revision Questions in BIOLOGY.

Ten questions to be answered in 15 minutes!

The CORRECT ANSWERS with their EXPLANATIONS will be released in 24 hours!


1 : The smallest living organisms which share the characteristics of both living and non living matter are ________?
A ) Bacteria.
B ) Fungi.
C ) Virus.
D ) Protozoa.

The answer is C because virus reproduces inside the cells of other living organisms, but exists as a crystal outside a living cell.


2 : The cell of an onion bulb can be differentiated from a cheek cell by the presence of _______?
A ) Plasmalemma.
B ) Chloroplast.
C ) Cell wall.
D ) Nucleus.

The answer is C because the cell of an onion bulb being a plant cell possesses cellulose while a cheek cell which is an animal cell does not.


3 : In a cell, the genes are carried by _______?
A ) Nuclear membrane.
B ) Lysosomes.
C ) Chromatin threads.
D ) Mitochondria.

The answer is C because chromosomes are thread-like materials located in the nucleus of a cell which carries the genes. It was discovered in 1912 by the American geneticist whose name is Thomas Morgan.


4 : The membrane surrounding the vacuole in a plant cell is called the _____?
A ) Plasmalemma.
B ) Tonoplast.
C ) Nuclear membrane.
D ) Endoplasmic reticulum.

The answer is B because a vacuole is surrounded by a membrane called tonoplast which is filled with water, mineral salts, sugars and pigments called cell sap.


5 : A group of similar cells performing the same function is _______?
A ) an organ.
B ) a tissue.
C ) a system .
D ) an organelle.
E ) an enzyme.

The answer is B because a tissue is a group of cells which are similar in structure and function.


6 : An amoeba and an unlaid chicken egg are _______?
A ) Animal tissues.
B ) Organelles.
C ) Single cells.
D ) Organisms.

The answer is C because both amoeba and an unlaid chicken egg are unicellular.


7 : The rods in the retina of the eye are examples of _______?
A ) Organs.
B ) Cells.
C ) Tissues.
D ) Systems.

The answer is B because rods and cones are cells present in the retina which is a tissue in the eye which is in turn an organ in the body.


8 : What is the level of organisation of an onion bulb _______?
A ) Tissue.
B ) Organ.
C ) Systemic.
D ) Organism.

The answer is B because onion bulb is a plant organ composed of aggregates of epithelial tissues. NOTE that, tissues which cover and protect the surface of plants are known as epithelial tissues.


9 : Which of the following does a virus have in common with animal cells____?
A ) Nucleus.
B ) DNA.
C ) Glycogen.
D ) Cytoplasm.

The answer is B because a virus possesses a strand of nucleic acid which may be DNA or RNA which is present in all other animal cells.


10 : The pioneer organisms in an ecological succession are usually the ______?
A ) Lichens.
B ) Algae.
C ) Ferns.
D ) Mosses.

The answer is A because the pioneer organism in a plant succession on bare rock surfaces are some species of crustose lichen, followed by foliose lichen and then mosses.

Orezy5:
PHYSICS

Corrections will be posted by 6pm tomorrow.


1. A convex mirror produces an image Which is one quarter the size of an object placed in front of it. If the radius of curvature of the mirror is 32cm, calculate the distance between the object and its image.

2. An object is located at a distance of 20cm from a concave mirror of radius of curvature 30cm. Calculate the distance between the object and its image.

3. For an object placed 6cm from a diverging lens of focal length 18cm, the image is ____

A. 4.5cm behind The lens
B. 4.5cm in front of the lens
C. 9cm in front of the lens
D. 9cm behind the lens


4. Determine the power of a concave lens with focal length 25cm.

Orezy5:
PHYSICS

Corrections will be posted by 6pm tomorrow.


1. A convex mirror produces an image Which is one quarter the size of an object placed in front of it. If the radius of curvature of the mirror is 32cm, calculate the distance between the object and its image.

2. An object is located at a distance of 20cm from a concave mirror of radius of curvature 30cm. Calculate the distance between the object and its image.

3. For an object placed 6cm from a diverging lens of focal length 18cm, the image is ____

A. 4.5cm behind The lens
B. 4.5cm in front of the lens
C. 9cm in front of the lens
D. 9cm behind the lens


4. Determine the power of a concave lens with focal length 25cm.

DrOptimistic:


Check my answer to the questions you posted before

Orezy5:

Checked All Correct