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​These are chemistry questions and answers categorized according to topics, papers i.e. Paper 1 and 2, Levels i.e. form 1 to form 4, kcse year the examination was done and section A or B
Select topic/category to open topical questions from that particular option provided. ​Chemistry Topics
You are provided with the following: thermometer, boiling tube, beaker, Bunsen burner, pure substance X whose boiling point is about 80°C, water and any other apparatus that may be required. Draw a labelled diagram of the set-up that can be used to determine the melting point of X.
ANSWERS
An experiment was Carried out to determine the presence of Substances P, Q, R and S in mixture T. The results obtained are shown in Figure 2.
(a) Ne the method of separation illustrated in Figure 2.
(b) Select: (i) one Substance Which Contains a Component not present in T. (ii) a substance which is least Soluble in the solvent used.
ANSWERS
(a)Chromatography/paper chromatography
(b)(i)Q (ii)S
Explain how a student can establish whether a liquid sample extracted from a plant is pure.
ANSWERS
When a student was stung by a nettle plant, a teacher applied an aqueous solution of ammonia to the affected area of the skin and the
student was relieved of pain. Explain.
ANSWERS
Describe an experimental procedure that can be used to extract oil from nut seeds.
ANSWERS
Crush grind using a pestle and mortar, add suitable solvent of propanone ethanol alcohol and stir to dissolve oil. Filter the mixture to obtain a solution of the oil. Leave the solution in the sun for propanone to evaporate leaving the oil.
​Name an appropriate apparatus that is used to prepare standard solutions in the laboratory. (1 mark)
Expected Response
​volumetric flask
​Related Chemistry Questions and Answers on Simple Classification of Substances Form 1 Level
Iron (III) oxide was found to be contaminated with copper (II) sulphate. Describe how a pure sample of iron (III) oxide can be obtained.
ANSWERS
The graph below is a cooling curve for water. Study it and answer the questions that follow
(a) Explain what happens to the molecules of water in the region BC in terms of kinetic theory.
(b) In what state is the water in the region DE?
ANSWERS
The molecules of water are
(a) Loosing heat . The kinetic energy decreases and the molecules move closer to each other (b) Solid state
Figure 5 shows an apparatus used to separate a mixture of water and hexene.
Expected Response
The set up below was used to separate a mixture of methanol and propanol. Study it and answer the question that follow.
a) State the function of X
b) Which liquid will collect first in the beaker? give a reason.
ANSWERS
Draw a set up that can be used to separate a mixture of sand and iodine
ANSWERS
The chromatogram below was obtained from a contaminated food sample P.
Contaminants Q, R, S and T are suspected to be in P. Use it to answer the following questions. 
a) Identify the contaminants in mixture P.
b) Which is the most soluble contaminant in P.?
ANSWERS
Describe an experiment procedure that can be used to extract oil from nut seeds
ANSWERS
Give a reason why phosphorus is stored under water.
Expected Response
To keep away air/ oxygen which would react with it
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January 2025
AuthorMaurice Atika is a teacher and a netprenuer. |
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