a) (i) W
(ii) Z
b) X
Kavungya answered the question on March 28, 2019 at 12:26
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(a) Atomic radii of alkaline earth metals are smaller than those of the corresponding alkali metals in the same period.
(b) Melting point...(Solved)
Briefly explain the following
(a) Atomic radii of alkaline earth metals are smaller than those of the corresponding alkali metals in the same period.
(b) Melting point of halogens increase down the group.
(c) Helium is a better gas for use in weather research balloons than hydrogen.
Date posted: March 28, 2019. Answers (1)
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Date posted: March 28, 2019. Answers (1)
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(a) Identify gas Z.
(b) Write the chemical equation for the reaction which produces gas Z
(c)...(Solved)
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(a) Identify gas Z.
(b) Write the chemical equation for the reaction which produces gas Z
(c) State why the above experiment should be carried out in a fume chamber.
Date posted: March 28, 2019. Answers (1)
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Study the scheme below hence answer the questions that follow.
(a) Identify solid Q.
(b) Write an ionic equation for the reaction in Step II.
(c) State the condition necessary for Step I.
Date posted: March 28, 2019. Answers (1)
- Name the method of separation that can most suitably be used to separate the following mixtures.
(a) Gasoline from petroleum
(b) Benzoic acid and potassium carbonate
(c) Oil...(Solved)
Name the method of separation that can most suitably be used to separate the following mixtures.
(a) Gasoline from petroleum
(b) Benzoic acid and potassium carbonate
(c) Oil from cashew nuts
Date posted: March 28, 2019. Answers (1)
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After sometimes, the cotton wools X, Y and Z changed color in turn.
(a) What were the...(Solved)
Study the set-up below and answer the questions that follow.
After sometimes, the cotton wools X, Y and Z changed color in turn.
(a) What were the colour changes?
(b) Which cotton wool changed colour first?
(c) Explain why the cotton wools did not change colour at the same time.
Date posted: March 28, 2019. Answers (1)
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A current of 2.5A was passed through a cell containing N2+ ions for 25 minutes. The mass of the cathode increased by 0.36g.Determine the R.A.M of N. (F = 9.65 x 104Cmolˉ¹).
Date posted: March 28, 2019. Answers (1)
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The diagram below represents a set-up of apparatus used to investigate the effect of electric current on lead (II) bromide.
Describe what is observed at electrode C.
Date posted: March 28, 2019. Answers (1)
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Date posted: March 28, 2019. Answers (1)
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Complete the table by indicating the numbers of electrons and neutrons.
Date posted: March 28, 2019. Answers (1)
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(a) What name is given to such a figure?
(b) Which part of the figure represents the change of state of naphthalene?
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Date posted: March 28, 2019. Answers (1)
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Describe how you will separate...(Solved)
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Describe how you will separate the three solids from a mixture of the three.
Date posted: March 28, 2019. Answers (1)
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Date posted: March 28, 2019. Answers (1)
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Calculate the volume of carbon (IV) oxide that would be produced if 15g of calcium carbonate reacted with 100cm³ of 2.0M hydrochloric acid (C = 12.0, O = 16.0, Ca = 40.0) molar gas volume = 24000cm³
Date posted: March 28, 2019. Answers (1)
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Date posted: March 28, 2019. Answers (1)
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(a) Graphite
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(a) Graphite
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Date posted: March 28, 2019. Answers (1)
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The diagram below illustrates how lithium would react with steam. Study it then answer the questions that follow.
(a) Write the equation for the reaction that takes place.
(b) Explain why this experiment cannot be carried out with potassium in the same way as shown.
Date posted: March 28, 2019. Answers (1)
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Date posted: March 28, 2019. Answers (1)
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(a) Write the electron arrangements of their ions, N3-, O2- and Na+....(Solved)
The atomic numbers of nitrogen, oxygen and sodium are 7, 8 and 11 respectively.
(a) Write the electron arrangements of their ions, N3-, O2- and Na+.
(b) Arrange the 3 ions in increasing order of size. Give a reason for your answer.
Date posted: March 28, 2019. Answers (1)
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The grid below is part of the periodic table. Study it and answer the questions that follow. The letters are not actual symbols of elements.
(a) What is the name given to the chemical family of element C?
(b) Would element B react with J? Explain.
(c) Compare the melting points of B and M.
Date posted: March 28, 2019. Answers (1)