a)Chlorine water changes colour from yellow to colourless
-Chlorine water decomposes to form hydrochloric acid and oxygen
b)-Bleaching agent
-Treatment of water
Githiari answered the question on September 18, 2017 at 08:04
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Highlight the steps followed when lighting a Bunsen burner
Date posted: September 18, 2017. Answers (1)
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isotope is 25 days.
(a) What is meant by...(Solved)
M grammes of a radioactive isotope decayed to 5 grammes in 100 days. The half life of the
isotope is 25 days.
What is meant by half life
Date posted: September 18, 2017. Answers (1)
- A student burnt magnesium ribbon in a gas jar full of sulphur (IV) oxide gas.
(i) State two observations made in the gas jar
(ii) Write an...(Solved)
A student burnt magnesium ribbon in a gas jar full of sulphur (IV) oxide gas.
(i) State two observations made in the gas jar
(ii) Write an equation for the reaction that took place
Date posted: September 18, 2017. Answers (1)
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realized that it did not lather easily.
(i) Name the...(Solved)
A student fetched water from a river in a limestone area. He used it for washing and
realized that it did not lather easily.
(i) Name the two ions that prevent lathering
ii)Given that the structure of soap is C17H35COONa.Explain by means of ionic equations how the above ions prevent lathering
Date posted: September 18, 2017. Answers (1)
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5.0g of calcium carbonate were allowed to react with 25cm3 of 1.0M hydrochloric acid until
there was no further reaction. Calculate the mass of calcium carbonate that remained
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Date posted: September 18, 2017. Answers (1)
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2X2(g) + Y2(g)<------> 2X2Y(g) H = -197kJ/mol
Suggest two ways of increasing the yield of X2Y(Solved)
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2X2(g) + Y2(g)<------> 2X2Y(g) H = -197kJ/mol
Suggest two ways of increasing the yield of X2Y
Date posted: September 18, 2017. Answers (1)
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Give two physical properties of hydrogen gas
Date posted: September 18, 2017. Answers (1)
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H2NCH2COOH + H2NCHCH3COOH ---------->H2O +---------
b)Name the type of polymerization...(Solved)
(a) Proteins are obtained from amino acids monomers. Complete the equation below to show the polymer formed.
H2NCH2COOH + H2NCHCH3COOH ---------->H2O +---------
b)Name the type of polymerization shown above
Date posted: September 18, 2017. Answers (1)
- Dry carbon (II) oxide gas was passed over heated lead (II) oxide.
(a) Write an equation for the reaction
(b) Give one industrial application of the above...(Solved)
Dry carbon (II) oxide gas was passed over heated lead (II) oxide.
(a) Write an equation for the reaction
(b) Give one industrial application of the above reaction.
(c) Name another gas that can be used in the above reaction.
Date posted: September 18, 2017. Answers (1)
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Explain the effects of the accumulation of nitrogenous compounds in water masses?
Date posted: September 18, 2017. Answers (1)
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Date posted: September 18, 2017. Answers (1)
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a)Why is the percentage of carbon(IV)oxide in the atmosphere fairly constant?
b)Calculate the volume of carbon(IV)oxide in 8,000 m3 of air contained in a
Date posted: September 18, 2017. Answers (1)
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Date posted: September 17, 2017. Answers (1)
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Date posted: September 16, 2017. Answers (1)
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Date posted: September 14, 2017. Answers (1)
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b)Calculate how long it would take an aqueous gold (III) chloride cell to coat 2.5 g of gold
on a...(Solved)
a)State the Faraday’s law of electrolysis
b)Calculate how long it would take an aqueous gold (III) chloride cell to coat 2.5 g of gold
on a bracelet using a current of 2.5 A. The half reaction has been provided for you.
c)Two half-cells are connected under standard conditions to make an electrochemical cell.
The two half-cells are a copper-copper (I) ion (Cu/Cu+) and an aluminum-aluminum ion (Al/Al3+). Using your the Standard Reduction Potentials below answer.
Al3+(aq) + 3e- → Al(s) -1.66 V
Cu2+(aq) + e- → Cu(s) 0.52 V
i)Write the cell diagram for the cell obtained when the two half cells are connected
ii)Identify which reaction is the anode and which is the cathode.
(iii)Calculate the emf for the cell
(iv)Write the overall balanced redox reaction for the electrochemical cell
d)An excess of copper solid is dropped into a solution which contains AgNO3 , Fe (NO3)3 and Zn (NO3)2. Write the ionic equations for any reduction half cell-reactions that occur over time under standard conditions
Date posted: September 14, 2017. Answers (1)
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a)Given that the mass of copper obtained in an o extraction was 210kg, determine the percentage purity of the ore used (copper pyrites) if 810kg of it was fed to the 1st roasting furnace. (Cu = 63.5, Fe = 56, S = 32.0)
b)Give 2 effects that the process above could have on the environment.
Date posted: September 14, 2017. Answers (1)
- A student found a bottle containing CH3CH2COOCH3.
(i)Name the process of formation of the substance above
ii)Identify the two substances from which the substance above is derived...(Solved)
A student found a bottle containing CH3CH2COOCH3.
(i)Name the process of formation of the substance above
ii)Identify the two substances from which the substance above is derived .
iii)Give one advantage and one disadvantage of using soapless detergent
iv)Explain briefly how the soapless detergents given above may be manufactured
Date posted: September 14, 2017. Answers (1)
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Date posted: September 14, 2017. Answers (1)
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Date posted: September 14, 2017. Answers (1)