Jhs science mock
Answer all the questions in this section
Jhs science mock examination questions and answers
a. The diagram below is an experimental setup to demonstrate that carbon (IV) oxide is needed for photosynthesis. Study the diagram carefully and answer the questions that follow
Jhs Science mock examination questions and answers
I. What was done to the potted plant before the experiment was setup?
II. Why was a transparent glass bottle used?
III. What was the role of the soda lime?
IV. What was the purpose of smearing Vaseline at the neck of the two flasks?
V. Why were the leaves left attached to the potted plant throughout the experiment?
VI. Explain why flask B was without soda lime.
VII. State and explain what would be observed when leaves from flask A and B are tested for starch after 3 hour.
VIII. Mention two other factors that are necessary for photosynthesis.
Solution to 1a. jhs science mock examination questions and answers
I. It was placed in darkness continuously for about 2 days. This was to de- starch the leave.
II. A transparent glass bottle was used so that the leaves would receive maximum amount of sunlight
III. To absorb all the carbon dioxide from the enclosed air in the flask.
IV. To prevent air from entering the flask.
V. To receive the necessary supply of water and mineral salts From the parent plant.
VI. Because it serves as the control experiment
VII. Leaf in flask A will remain colourless. This is because it contains no starch. Leaf from flask B will turn blue-black. This is because it contains starch
VIII. Light and chlorophyll
b. The diagram below represents a setup of an experiment in which some quantity of hydrochloric acid was added to sodium hydroxide solution of the same concentration. Study the diagram carefully and answer the questions that follow
I. Identify the parts labeled I_.IV
II. Mention one instrument that Could be used for transferring sodium hydroxide solution into III.
III. Provide the name of the reaction that occurred between dilute hydrochloric acid and sodium hydroxide solution.
IV. What compound would be left.in the evaporating dish if the liquid mixture IV is heated?
V. Write a balanced chemical equation for the reaction between the hydrochloric acid and IV.
VI. Name two substances produced after the reaction
Solution to 1b. Jhs science mock examination questions and answers
I. i.retord stand
Ii. Burrett
iii. Conical flask
iv. Sodium hydroxide solution ( NaOH)
II. Pipette
III. Neutralization reaction
IV. Sodium chloride
V. NaOH + HCl_NaCl + H2O
VI. _salt ( sodium chloride NaCl)
_water ( H2O)
b. study the laboratory apparatus carefully and answer the questions that follow
I. Identify the laboratory apparatus A, B, C, D, E and F.
II. State One Use of each of A, B, D and F.
Solution to 1c. Jhs science mock examination questions and answers
I. A- dropping or treat pipette
B- volumetric flask.
C- funnel
D- separating funnel
E- tripod stand
F-pipette.
b. Device A is used for releasing reagents or chemical solutions in drops
Device C is used transferring or collecting liquid from one container into another
Device D is used for separating immiscible liquids
Device F is used for drawing specific volume of liquid from one container into another.
b.A Farmer used the crops A, B, C and D in crop rotational program for for successive growing seasons.
Jhs science mock examination questions and answers
I. Identify each of the crops A, B, C and D in the above
II. Draw a table to give a possible sequence of the crops during the four growing seasons.
III. Explain the importance of crop B in the cropping program
IV. Give one advantage the farmer is likely to gain by adopting the crop rotational program.
Solution to 1d. Jhs science mock examination questions and answers
I. _A- tomorrow
_ B- beans
_C- cabbage
_D- carrot.
II. 
III. It adds nitrogen into the soil
IV. _ controls soil erosion
_maintain soil fertility
_weeds are easily controlled
_ prevents leaching
_ improves soil texture and structure
Bece science mock 7 questions and answers
2.a. I. State the law of floatation
Ii.Why a balloon filled with hydrogen gas will float in air?.
bi. State two difference between food chain and food web
Ii. State the difference between ecosystem Chain and a habitat
c. Study the diagram below and answer the questions that follow
I. Identify the crop pest above
Ii. Give three examples of crops attached by the organisms.
III. Mention two methods of controlling the pest
d.i. What is the difference between homogeneous and heterogeneous mixtures.
Ii. Why is air said to be a mixture
Solution to q2. Jhs science mock examination questions and answers
a. I. The law of floatation states that a floating displaces an amount of fluid equal to its weight
Ii. Balloon filled with hydrogen gas will float in air because hydrogen gas is less denser than air, from the law of floatation, the denser air will displaces the balloon upwards until equilibrium is achieved.
b.i.- food chain is simple but food is complex.
– food chain is the linear feeding relationships but food web is the linking of two or more food chains.
-the absence of one organism with affect food chain but in food the absence of one organism may not affect the feeding relationship in the web.
Ii. Ecosystem involves living and nonliving organisms living in their natural habitat and the relationship that exists between them while a habitat is a natural dwelling place of a particular organism.
c. I. Rat/mouse
Ii. – cassava
_maize
_rice
_cocoa
II. _Chemical method- using rodenticides to kill them.
_biological method_ introducing predators to hunt the rodents
_ cultural method_fencing around the farm, proper spacing of crops and weed control
d.l. homogeneous mixture is the uniform mixture of two or more substances ( solute and solvent) but heterogeneous mixture is the nonuniform mixture of two or more substances (solute and solvent).
Ii. Air is a mixture because:
– it involves the physical combination of gases.
– The components can be separated by physical means.
Jhs science mock examination questions and answers
3a.i.what is a vaccum flask?
Ii. Draw and label a diagram of a vacuum flask.
b. Explain how the vaccum flask minimizes heat loss and heat gain.
Solution. Jhs science mock examination questions and answers
a.i.vaccum flask is a device used to store cold or hot substances.
Ii. 
d. – the cork reduces heat loss through conduction and convection
– silvered walls reduce heat loss through radiation
_vacuum reduces heat loss by conduction and convection.
4a. Explain the following observations:
I. A a boy holding a long metal rod with one end in fire feels a burning sensation in the palm.
Ii. A clinical thermometer breaks when used to measure the temperature of boiling water.
Solution. Jhs science mock examination questions and answers
I. A metal is a good conductor of heat. Heat travels from one end of the metal rod in fire to the opposite end. Nerve cells which are sensitive to heat in the palm are stimulated and then heat is felt in the palm.
Ii. Clinical thermometer has a narrow temperature range (34•C to 46•C). Water boils at 100°C which is higher than the upper temperature limit of the clinical thermometer. The mercury in the bulb expands and begins to evaporate with the resultants pressure causing the glass tube to beak
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