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Use the following information to answer the questions that follow.
(Solved)
Use the following information to answer the questions that follow.
a) Draw an energy cycle diagram and label the various heat changes.
b) Use the energy circle above to calculate heat of formation of methanol.
Date posted:
September 18, 2019
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Answers (1)
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Differentiate between a monomer and polymer.
(Solved)
Differentiate between a monomer and polymer.
Date posted:
September 18, 2019
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Answers (1)
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Pentanoic acid reacts with butan – 1 – 0l to form an organic compound.
(Solved)
Pentanoic acid reacts with butan – 1 – 0l to form an organic compound.
(i) Write an equation to show the above reaction.
(ii) What is the name given to the above type of reaction?
(iii) A few drops of a certain catalyst must be added to the mixture to increase the rate of the reaction.
(a) Name the catalyst.
(b) Explain the role of the catalyst in the above reaction.
Date posted:
September 18, 2019
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Answers (1)
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Two methods of preparing alkenes are shown by the following general equations.
(Solved)
Two methods of preparing alkenes are shown by the following general equations.
(a) What type of reactions are described by equations;
(i)and (ii)
(b) Which of the two methods is used on a large scale.
Date posted:
September 18, 2019
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Answers (1)
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You are provided with the following electrode potentials of four half-cell reactions. Letters do not represent the actual symbol of the element
(Solved)
You are provided with the following electrode potentials of four half-cell reactions. Letters do not represent the actual symbol of the element
(a) Identify the strongest reducing agent. Explain.
(b) Calculate the emf of the two half cells that when combined would produce the largest emf.
Date posted:
September 17, 2019
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Answers (1)
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The structure below represents a portion of polyphenylethene.
(Solved)
The structure below represents a portion of polyphenylethene.
Draw the structure of the monomer and name it.
Date posted:
September 17, 2019
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Answers (1)
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Draw the structures of the following compounds.
i) Ethylbutanoate
ii) 3-ethyl – 3 – methyl hexane
(Solved)
Draw the structures of the following compounds.
i) Ethylbutanoate
ii) 3-ethyl – 3 – methyl hexane
Date posted:
September 17, 2019
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Answers (1)
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The standard electrode potentials for certain half cell reactions are shown below.
(Solved)
The standard electrode potentials for certain half cell reactions are shown below.
(a) (i) Identify the strongest oxidizing agent.
(ii) Write the cell equation for a cell formed by connecting W and X cells.
(iii) Calculate the e.m.f of cell in a(ii) above.
(b) During electrolysis of silver nitrate, a current of 0.5A was passed through the electrolyte for 3 hours.
(i) Write the equation for the reaction which took place at the anode.
(ii) Calculate the mass of silver deposited. (Ag = 108, IF = 96500C)
(iii) Give two reasons why it is necessary to electroplate iron with silver.
Date posted:
September 17, 2019
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Answers (1)
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A sample of air contains nitrogen, oxygen and argon. Describe how oxygen gas can be obtained.
(Solved)
A sample of air contains nitrogen, oxygen and argon. Describe how oxygen gas can be obtained.
Date posted:
September 17, 2019
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Answers (1)
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100cm3 of0.05M Sulphuric (VI) acid were placed in the flask and small quantity of potassium Carbonate added. The mixture was boiled to expel all carbon...
(Solved)
100cm3 of0.05M Sulphuric (VI) acid were placed in the flask and small quantity of potassium Carbonate added. The mixture was boiled to expel all carbon (IV) oxide. 25cm3 of the resulting solution required 18cm3 of 0.1M potassium hydroxide solution to neutralize it. Calculate the mass of potassium carbonate added. (K = 39, O = 16, C = 12)
Date posted:
September 17, 2019
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Answers (1)
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12.3.0g of an organic compound containing Carbon, hydrogen and oxygen only produced 4.4g of Carbon (IV) oxide and 1.8g of water on complete combustion.
a) Calculate...
(Solved)
12.3.0g of an organic compound containing Carbon, hydrogen and oxygen only produced 4.4g of Carbon (IV) oxide and 1.8g of water on complete combustion.
a) Calculate its empirical formula.
b) Calculate in molecular formula if its formula mass is 60.
Date posted:
September 17, 2019
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Answers (1)
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The products formed by action of heat on nitrates of element X, Y and Z are shown below.
(Solved)
The products formed by action of heat on nitrates of element X, Y and Z are shown below.
a) Arrange the metals in order of increasing reactivity.
b) Which element forms a soluble carbonate?
c) Give an element that can be Y.
Date posted:
September 17, 2019
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Answers (1)
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a) Draw a diagram to show how an iron ring can be electroplated with pure silver.
b)Give two reasons why electroplating is necessary.
(Solved)
a) Draw a diagram to show how an iron ring can be electroplated with pure silver.
b)Give two reasons why electroplating is necessary.
Date posted:
September 17, 2019
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Answers (1)
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Consider the flow chart below; use it to answer the questions that follow.
(Solved)
Consider the flow chart below; use it to answer the questions that follow.
(i) State the most likely identity of solid F.
(ii) Write the chemical equation for the reaction between solid F and concentrated nitric (v) acid.
(iii) Name
Solution N
Solution H
(iv) Write the formula of solution N.
Date posted:
September 17, 2019
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Answers (1)
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Propane is a hydrocarbon. What does the term hydrocarbon mean?
(Solved)
Propane is a hydrocarbon. What does the term hydrocarbon mean?
Date posted:
September 17, 2019
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Answers (1)
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Name the class to which the following cleansing agents belong.
(Solved)
a)Name the class to which the following cleansing agents belong.
b) Which cleaning agent between (i) or (ii) above is preferred for cleaning garments while using water from a dam containing dissolved calcium chloride? Explain
Date posted:
September 17, 2019
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Answers (1)
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Describe how a solid mixture of Zinc sulphate and lead (ii) Sulphate can be separated into Solid samples.
(Solved)
Describe how a solid mixture of Zinc sulphate and lead (ii) Sulphate can be separated into Solid samples.
Date posted:
September 17, 2019
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Answers (1)
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The pH values of some solutions labeled K,H,L,P and R are given in the table below. Use the information to answer the questions that follow.
(Solved)
The pH values of some solutions labeled K,H,L,P and R are given in the table below. Use the information to answer the questions that follow.
(a)Identify the solution with the highest concentration of hydroxyl ions.
(b)Which solution is likely to be sodium chloride solution?
(c)Which solution would react most vigorously with magnesium metal?
Date posted:
September 17, 2019
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Answers (1)
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Use the diagram below to answer the questions that follow:
(Solved)
Use the diagram below to answer the questions that follow:
a) Identify the radiations
A
C
b)The table below gives the rate of decay for a sample of radioactive element K. Study it and answer the question that follows:
Determine the half-life of element K.
Date posted:
September 17, 2019
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Answers (1)
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Other than cost and ability to conduct, give two other reasons why aluminum is used for making overhead electric cables while magnesium is not.
(Solved)
Other than cost and ability to conduct, give two other reasons why aluminum is used for making overhead electric cables while magnesium is not.
Date posted:
September 17, 2019
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Answers (1)