i) From purple to colourless.
ii) Potassium manganate (VII) to cause the colour change.
maurice.mutuku answered the question on September 26, 2019 at 05:12
- Name the following compounds.(Solved)
Name the following compounds.
Date posted: September 25, 2019. Answers (1)
- Below is a list of major components of crude oil and their boiling points.(Solved)
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. Answers (1)
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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. Answers (1)
- 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...(Solved)
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. Answers (1)
- A student wrongly categorised air as a compound and not as a mixture. Give two reasons as to why the student was wrong.(Solved)
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. Answers (1)
- Two hydrocarbons compounds are represented by the formulae C4H8 and C4H10
Which of the compounds is saturated;
Explain(Solved)
Two hydrocarbons compounds are represented by the formulae C4H8 and C4H10
Which of the compounds is saturated;
Explain
Date posted: September 25, 2019. Answers (1)
- Draw the following structure.
2-bromo-4-methylpent-2-ene
(Solved)
Draw the following structure.
2-bromo-4-methylpent-2-ene
Date posted: September 25, 2019. Answers (1)
- 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...(Solved)
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. Answers (1)
- The chromatogram below shows the constituents of a flower extract. Study it and answer the question that follows.(Solved)
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. Answers (1)
- 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.(Solved)
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. Answers (1)
- 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...(Solved)
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. Answers (1)
- Half-life of a radio-active elements is 30 days. Calculate the time required for its activity 37.5 counts per minute.(Solved)
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. Answers (1)
- During an electrolysis of Zinc sulphate using inert electrodes, a current of 0.5A was passed for 40 minutes on a steady current.
a) Write down the...(Solved)
During an electrolysis of Zinc sulphate using inert electrodes, a current of 0.5A was passed for 40 minutes on a steady current.
a) Write down the equation at the cathode.
b) Calculate the volume produced at the cathode given that 1F = 96,500c, MGV = 22.4 litres.
Date posted: September 25, 2019. Answers (1)
- The diagram below was used to prepare and collect Sulphur (IV) oxide gas.(Solved)
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. Answers (1)
- Study the flow chart given below.(Solved)
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. Answers (1)
- The table below shows the electrical conductivity of substances A, B and C.(Solved)
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. Answers (1)
- 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...(Solved)
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. Answers (1)
- Study the flow chart below and answer the question that follows.(Solved)
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. Answers (1)
- 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.(Solved)
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. Answers (1)
- A compound contains 29.1% sodium, 40.5% sulphur and the rest is oxygen. Find the empirical formulae.
(Na = 23, S = 32, O = 16)(Solved)
A compound contains 29.1% sodium, 40.5% sulphur and the rest is oxygen. Find the empirical formulae.
(Na = 23, S = 32, O = 16)
Date posted: September 25, 2019. Answers (1)