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a) A, D have the same number of valence electrons (belong to the same group 2 )
(b) B2O
(c) B has more than 3 valence electrons
(d) (i) Strongest reducing agent is C. It’s the most electropositive or has the least
electrostate/electromagnetic forces hence has the highest abilityv1/2 to lose its valence
electrons
(ii) Oxidising agent is B. Has the highest ability to form negatively charged ion. Highest
ability to gain electrons up the valence energy level
(e) Ionic radius of D is less than of C due D has highest electrostatic force or greater nuclear
charge, hence the valence energy level is greatly attracted in D than in C after forming its ion
inwardly contracting the D valence energy level.
(f) Form ion by gaining electrons the , the gained electrons are being repelled by the others in
the inner energy levels and even in the same energy level. Hence making the ionic radius to
expand outwardly due to repulsive forces. Hence the atomic radius being less than its
ionic radius.
(g) (i) A and D alkali earth metals.
(ii) B halogens.
(iii) C alkali metals.
(h) B (chlorine)
- Manufacture of HCl acid.
- Disinfectant.
- Water treatment.
sharon kalunda answered the question on May 20, 2019 at 05:57
- The diagram below represents an incomplete paper chromatogram of pure dyes X, Y, Z and
mixture W.(Solved)
The diagram below represents an incomplete paper chromatogram of pure dyes X, Y, Z and
mixture W.
Mixture W contains dyes Y and Z only. Complete the chromatogram to show how mixture
W separates.
Date posted: May 20, 2019. Answers (1)
- The flow chart below outlines some of the process involved during extraction of copper.(Solved)
The flow chart below outlines some of the process involved during extraction of copper.
a) (i) Write the formula of copper pyrite.
(ii) Name liquid T
(iii) Write equations for the reactions taking place in the 2nd roasting furnace.
(iv) Identify substance B and write equation for the reaction that take place in the smelting furnace.
(v) State the purpose of substance F.
Date posted: May 20, 2019. Answers (1)
- The atomic number of sulphur is 16. Write the electron arrangement of sulphur in the
following:(Solved)
The atomic number of sulphur is 16. Write the electron arrangement of sulphur in the
following:
Date posted: May 17, 2019. Answers (1)
- Study the reduction potentials below.
(i) Identify the weakest oxidizing agent.
(ii) Calculate the e.m.f of the cell that would produce the highest output of voltage.
(iii)...(Solved)
Study the reduction potentials below.
(i) Identify the weakest oxidizing agent.
(ii) Calculate the e.m.f of the cell that would produce the highest output of voltage.
(iii) Write the cell diagram for the cell formed above.
Date posted: May 17, 2019. Answers (1)
- Study the diagram below and answer the questions which follow.(Solved)
Study the diagram below and answer the questions which follow.
(i) State two observations made when hydrogen gas pass over hot lead II oxide.
(ii) Write the equation for the reaction which occurs in the combustion tube.
(iii) What property of hydrogen is shown in the experiment above
(iv) Identify liquid M.
(v) What type of reaction occurs when hydrogen gas reacts with butene?
(vi) State the condition required for the reaction (v) above
(vii) Apart from hydrogen peroxide, state two other reagents that can be used to prepare
oxygen gas.
(viii) Write an equation to show how hydrogen gas is formed from the reagents chosen in
(vii) above.
Date posted: May 17, 2019. Answers (1)
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What is atomicity?
Date posted: May 17, 2019. Answers (1)
- Study the periodic grid below and answer the questions which follow. The letters do not
represent actual symbols of the elements.(Solved)
Study the periodic grid below and answer the questions which follow. The letters do not
represent actual symbols of the elements.
(i) To which category of elements does element N belong?
(ii) Compare the atomic radius of element U and X. Explain.
(iii) An ion A3- has a configuration of 2.8. Place element A on the grid above.
(iv) Which of the group 1 elements will require the greatest amount of energy to
remove the outermost electron. Explain.
(v) Why is element Z used in light bulbs?
(vi) Write the formula of the phosphate of element T.
(vii) State the type of structure found in the oxide of element F.
Date posted: May 17, 2019. Answers (1)
- A given amount of propane was used to heat one litre of water. The temperature of
the water rose from 25oC to 50.5oC. (S.H.C of water...(Solved)
A given amount of propane was used to heat one litre of water. The temperature of
the water rose from 25oC to 50.5oC. (S.H.C of water = 4.2J/g/k)
(i) Calculate the heat change for the reaction.
(ii) Find the mass of propane burnt (C=12, H=1)
Date posted: May 17, 2019. Answers (1)
- Study the heats of combustion shown below.(Solved)
Study the heats of combustion shown below.
Draw an energy cycle diagram linking heat of formation of propane with its heat of
combustion and the heat of combustion of the constituent elements.
Date posted: May 17, 2019. Answers (1)
- Define standard heat of combustion of a substance.(Solved)
Define standard heat of combustion of a substance.
Date posted: May 17, 2019. Answers (1)
- Study the diagram below. State and explain the observation made after sometime(Solved)
Study the diagram below.
State and explain the observation made after sometime.
Date posted: May 17, 2019. Answers (1)
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Give an equation to show how chlorine forms bleaching powder.
Date posted: May 17, 2019. Answers (1)
- Chlorine reacts with cold dilute sodium hydroxide to form a bleaching agent.
Name the bleaching agent.(Solved)
Chlorine reacts with cold dilute sodium hydroxide to form a bleaching agent.
Name the bleaching agent.
Date posted: May 17, 2019. Answers (1)
- The set up below was used to prepare chlorine gas. (i) Identify solid M (ii) What is the role of water in the experiment?.....(Solved)
The set up below was used to prepare chlorine gas.
(i) Identify solid M
(ii) What is the role of water in the experiment?
(iii) Complete the set up to show how dry chlorine gas can be collected
(iv) Write a chemical equation to show how chlorine gas is formed.
Date posted: May 17, 2019. Answers (1)
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State one use of lead.
Date posted: May 17, 2019. Answers (1)
- Pure lead can be obtained by electrolysis. Identify the anode and cathode for the
process.(Solved)
Pure lead can be obtained by electrolysis. Identify the anode and cathode for the
process.
Date posted: May 17, 2019. Answers (1)
- The flow chart below summarizes the process of extraction of lead from a chief ore.(Solved)
The flow chart below summarizes the process of extraction of lead from a chief ore.
(i) Identify process T
(ii) Give the name of:
Gas N
Solid F
(iii) Give two functions of CaCO3 in the extraction process.
(iv) Write an equation to show how waste product J is formed.
Date posted: May 17, 2019. Answers (1)
- Name any two ores of lead.(Solved)
Name any two ores of lead.
Date posted: May 17, 2019. Answers (1)
- a)Write down the electron arrangement for an atom of element U which has a mass number 14 and
contains 8 neutrons.(Solved)
a)Write down the electron arrangement for an atom of element U which has a mass number 14 and
contains 8 neutrons.
(b) Draw the structure of an atom of A given in (a) above.
Date posted: May 17, 2019. Answers (1)
- A sealed glass tube containing 250 cm3 of nitrogen gas at r.t.p was immersed in boiling water. Calculate the pressure inside the tube if the...(Solved)
A sealed glass tube containing 250 cm3 of nitrogen gas at r.t.p was immersed in boiling water. Calculate the pressure inside the tube if the volume of the gas does not change due to expansion of glass. (Room pressure=760mmHg, room temperature=298K).
Date posted: May 17, 2019. Answers (1)