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Complete the table below for the characteristics of the sub atomic particles.
Date posted:
October 1, 2019
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The flow chart below illustrates two industrial processes, Haber process and the Contact process:
(a) (i) Give the name of the process by which air is seperated into oxygen and nitrogen
(i) Apart from oxygen and nitrogen gases produced from process (a)(i) name one other gas produced
(b) Name the substances represented by the letters A, B, C and D
(c) Name the catalysts used in:
(i) Haber Process
(ii) Contact Process
(d) Explain the role of the catalysts in both the Haber and the Contact processes
(e) Write a chemical equation for the formation of compound B
(f) Calculate the percentage by mass of the nitrogen present in compound D
(g) Give one major use of compound D
Date posted:
October 1, 2019
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Study the set-up below and answer the questions that follow.
a) (i) Name Gas X
(ii) State the effect of releasing gas X to the environment
b) Write down equations for the reactions taking place in;
(i) Tube I
(ii) Tube II
(iii) Flask
c) State the observation made in tube III
d) Write down an equation for the reaction which could be used to generate Carbon (IV) Oxide for the above set up
(e) Name the reagents used to generate gas X in the laboratory
(f) Complete the diagram above to show how excess gas X can be collected
Date posted:
October 1, 2019
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The grid below shows a part of the periodic table. The letters do not represent the actual symbols. Use it to answer the questions that follow:-
a) How do the atomic radius of element
(i) X and M compare. Explain.
(ii) U and Q. Explain
b) Which letter represent the most reactive metal. Explain.
Date posted:
October 1, 2019
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The number of protons, neutrons and electrons in atoms A to F are given in the table below the letters do not represent the actual symbol of the elements:-
Choose from the table the letters that represent:
(i) An atom of a metal
(ii) A neutral atom of a non-metal
(iii) An atom of a noble gas
(iv) A pair of isotopes
(v) A cation
(vi) Anion
Date posted:
October 1, 2019
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When zinc is heated to redness in a current of steam, hydrogen gas is obtained. Write an equation for the reaction
Date posted:
October 1, 2019
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Hydrogen burns in oxygen to form an oxide.
(i) Write an equation for the reaction
(ii) State two precautions that must be taken before the combustion begins and at the end of
the combustion.
Date posted:
October 1, 2019
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Hydrogen can be prepared by reacting zinc with dilute hydrochloric acid.
a) Write an equation for the reaction.
b) Name an appropriate drying agent for hydrogen gas.
c) Explain why copper metal cannot be used to prepare hydrogen gas.
Date posted:
October 1, 2019
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Using dots(•) and crosses(x), show bonding in magnesium chloride.
Date posted:
September 27, 2019
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Distinguish between simulation and virtual reality
Date posted:
September 26, 2019
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Study the flow chart below and answer the questions that follow.
i) Name Compound T
ii) Gas U
iii) The equation below shows the reaction between sulphur (IV) oxide gas and oxygen gas to produce sulphur (VI) oxide in contact process.
2 SO2(g) + O2(g)----->2SO3 D = -197 kJ/mol
State two conditions that are necessary for maximum production of SO3.
iv) Name the catalyst used for this reaction.
Date posted:
September 26, 2019
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Study the reaction scheme below and use it to answer the questions that follow.
i) Name the process in;
Step I
Step II
ii) State the reagent necessary for the process in
Step II
Step III
iii) Name the type of reaction taking place in step III
Date posted:
September 26, 2019
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Castor oil extracted from castor seeds is found to change the colour of acidified potassium manganate (VII) .
i) State the colour change.
ii) Explain why castor oil reacts with acidified Potassium manganate (VII) to cause the colour change.
Date posted:
September 26, 2019
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Name the following compounds.
Date posted:
September 25, 2019
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Below is a list of major components of crude oil and their boiling points.
i) What is the name of the process by which the constituents of crude oil can be separated?
ii) Give one use of the gases component.
iii) Give the order by which the components are obtained from the mixture, starting with the first.
Date posted:
September 25, 2019
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The chromatogram below was obtained from a plant extract. Use it to answer the questions that follow.
i) Name line W
ii) What does the dotted line represent?
iii) State with a reason the least soluble dye in the moving solvent.
Date posted:
September 25, 2019
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The table below shows the results obtained when four solvents were used to separate a dye. Study the results and use them to answer the questions that follow.
i) Identify the most suitable solvent for this separation. Give a reason for your answer.
ii) What does the result of the solvent C tell us about the dye?
Date posted:
September 25, 2019
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A student wrongly categorised air as a compound and not as a mixture. Give two reasons as to why the student was wrong.
Date posted:
September 25, 2019
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Draw the following structure.
2-bromo-4-methylpent-2-ene
Date posted:
September 25, 2019
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A compound was analysed and found to contain 24.27% carbonate, 4.08% hydrogen and the rest is chlorine. If the molar mass of the compound is 99.0, calculate the molecular formula.
(C = 12, H = 1, Cl = 25.5)
Date posted:
September 25, 2019
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The chromatogram below shows the constituents of a flower extract. Study it and answer the question that follows.
Give a reason to explain the different positions of red and yellow pigments.
Date posted:
September 25, 2019
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A mixture of substance K (density 0.626g/cm3) and Z (density 0.85g/cm3) was allowed to settle in a container as shown below.
a) Which liquid forms layer (I)
b) Explain your answer in (a) above.
Date posted:
September 25, 2019
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The table below is a part of the periodic table. The letters are not the actual symbols of the element. Study it and answer the questions that follow.
a) Select an element which is the most reactive.
b) How do the ionic radius of T and S compare? Explain.
Date posted:
September 25, 2019
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Half-life of a radio-active elements is 30 days. Calculate the time required for its activity 37.5 counts per minute.
Date posted:
September 25, 2019
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The diagram below was used to prepare and collect Sulphur (IV) oxide gas.
a) Identify solid M.
b) State two properties of SO2 that makes possible to be collected in the method shown.
c) What are the optimum conditions of conversion of SO2 to SO3.
Date posted:
September 25, 2019
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Study the flow chart given below.
a) Name substance B.
b) Give one us of product C.
c) Write the equation between substance B to form substance C.
Date posted:
September 25, 2019
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The table below shows the electrical conductivity of substances A, B and C.
a) Give the type of structure and bonding that is present in substance A.
b) Which substance is likely to be sodium chloride. Explain.
c) Which one of the substance is likely to be plastic?
i) Explain why the substance you have given in (c) above behaves in the way it does
d) Give the type of structure and bonding that is present in substance A
Date posted:
September 25, 2019
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A student used the set-up shown in the diagram below in order to study the reactions of some metals with steam. The experiment was carried out for ten minutes.
a) What observation would be made if gas H was ignited.
b) When the experiment was repeated using lead powder instead of Beryllium very little of gas H was obtained. Give a reason for this observation.
c) Name another gas which is used together with hydrogen in welding.
Date posted:
September 25, 2019
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Study the flow chart below and answer the question that follows.
Identify
i) Solid V
ii) Solution R
iii) Solution Q
Date posted:
September 25, 2019
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Calculate the maximum volume of oxygen, measured at s.t.p., that can be obtained by heating a solution
containing 8.8g of hydrogen peroxide.
Date posted:
September 25, 2019