(i) A vaccum – cleaner filters dust from the air. The dust particles are trapped in a fabric or paper bag, while the purified air passes through it.
(ii) In water works, water is filtered before it is pumped to the consumers. This is done by employing simple filtration. Water is allowed to seep through a filter bed of fine sand and gravel in order to remove small particles from it.
(iii) In the car engine oil is filtered before use.
Kavungya answered the question on March 25, 2019 at 08:07
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(i) Describe the changes along regions A, B, C...(Solved)
The time – temperature graph obtained when ice was heated to its boiling point is given below.
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(ii) Explain why both B and D levelled off?
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(i) Oily and greasy –
(ii) Blood stains –...(Solved)
Name
(a) Cleansing agents for removing these stains from your school dress:
(i) Oily and greasy –
(ii) Blood stains –
(iii) Perspiration stains –
(b) A drying agent for ammonia gas –
(c) A solvent for paint –
(d) A gas which cannot be collected over water –
(e) A solid that sublimes –
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(a) Coloured extracts of grass dissolved in ethanol.
(b) Kerosine from Crude oil.
(c) Paraffin from water.
(d)...(Solved)
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(a) Coloured extracts of grass dissolved in ethanol.
(b) Kerosine from Crude oil.
(c) Paraffin from water.
(d) Iron filings from Sulphur powder.
(e) Ammonium chloride from Sodium chloride.
(f) Seawater, to obtain salt.
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i) What is the purpose of filtration unit I
ii) What is the name of process X
What is the purpose of
I.Process X
II.Addition of sodium hypochlorite
b) A sample of tap water was found to contain magnesium sulphate.
i) What type of hardness was present in the water?
ii) Explain how the hardness can be removed.
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ii) State one use of calcium carbonate.
Date posted: March 19, 2019. Answers (1)
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ii) Identify the ions and cations in the solution.
iii) On the diagram label the cathode.
iv) Write ionic equations for the reactions that took place at the anode
v) Explain the change that occurred to the Copper (II) Sulphate solution during the experiment.
vi) During the electrolysis a current of 2 amperes was passed through the solution for 4 hours. Calculate the volume of the gas produced at the anode. (1 Faraday = 96500 coulombs and volume of gas at room temperature is 24000cm3 )
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Date posted: March 19, 2019. Answers (1)
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(a) Write the electron arrangement of the elements Q and...(Solved)
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(a) Write the electron arrangement of the elements Q and R
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Date posted: March 19, 2019. Answers (1)
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The mixture K contains substances W and X only. Indicate on the diagram the chromatogram of K.
(b) State one application of chromatography.
Date posted: March 19, 2019. Answers (1)
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(b)Draw a dot (•) and cross (×) diagram to show bonding in compound farmed.
Date posted: March 19, 2019. Answers (1)
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(b)Explain your answer in (a) above.
Date posted: March 19, 2019. Answers (1)
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Moist hydrogen sulphide gas was passed through a tube containing wet sulphur (IV) oxide gas as shown below.
(a) State the observation (s) made.
(b) Write an equation for the reaction above.
(c) Giving a reason, which substance undergoes reduction above.
Date posted: March 19, 2019. Answers (1)