i) Liquid L is water
ii) Black copper (II) oxide changes to red brown.
iii) 2NH3(g) + 3CuO(s) $\rightarrow$ 3Cu(s) + N2(g) + 3H2O(l)
iv) The excess ammonia from the reaction dissolves in the water in the beaker to form ammonium hydroxide
which is a weak alkali
johnmulu answered the question on April 15, 2017 at 07:09
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The table below gives some properties of gases D and E.
(Solved)
The table below gives some properties of gases D and E.
a) Describe how you would obtain a sample of E from a mixture of gases D and E.
b) Suggest a possible identify of gas D. Give a reason for your answer.
Date posted:
April 15, 2017
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Answers (1)
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Study the flow chart below and answer the questions that follow.
(Solved)
Study the flow chart below and answer the questions that follow.
a) Identify: (i) X (ii) Y
b) State two uses of polyvinylchloride.
Date posted:
April 15, 2017
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Answers (1)
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Brownian motion of smoke particles can be studied by using the apparatus shown in Figure 9. To observe the motion, some smoke is enclosed in the smoke cell and then observed through the microscope.
(Solved)
Brownian motion of smoke particles can be studied by using the apparatus shown in Figure 9. To observe the motion, some smoke is enclosed in the smoke cell and then observed through the microscope.
(a) Explain the role of the smoke particles, lens and microscope in the experiment.
(b) State and explain the nature of the observed motion of the smoke particles.
(c) State what will be observed about the motion of the smoke particles if the temperature surrounding the smoke cell is raised slightly
Date posted:
April 13, 2017
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Answers (1)
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A can with a hole on the side is filled with water to a certain height. Water jets out as shown in figure 4 (a). A second identical can is filled with water to the same height and a block of wood floated on the water as shown in Figure 4 (b)
(Solved)
A can with a hole on the side is filled with water to a certain height. Water jets out as shown in figure 4 (a). A second identical can is filled with water to the same height and a block of wood floated on the water as shown in Figure 4 (b)
State the reason why the maximum distance of the jet, d2 is greater than d1
Date posted:
April 13, 2017
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Answers (1)
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Figure 15 shows a metal bolt which is threaded.
(Solved)
Figure 15 shows a metal bolt which is threaded.
Date posted:
April 13, 2017
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Answers (1)
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Figure 1 shows the change in volume of water in a measuring cylinder when an irregular solid is immersed in it.
(Solved)
Figure 1 shows the change in volume of water in a measuring cylinder when an irregular solid is immersed in it.
Given that the mass of the solid is 567 g, determine the density of the solid in gcm-3
(Give your answer correct to 2 decimal places).
Date posted:
April 13, 2017
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Answers (1)
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The figure below represents the set up that was used to crack an alkane
(Solved)
The figure below represents the set up that was used to crack an alkane
a) What was the purpose of the sand?
b) After some time, a colourless gas G collected in the test-tube. Describe a chemical test and observations that would be made in order to identify the class of compounds to which gas G belongs.
Date posted:
April 12, 2017
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Answers (1)
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Study the flow chart below and answer the questions that follow.
(Solved)
Study the flow chart below and answer the questions that follow.
a) Identify N and P.
b) What name is given to the type of halogenation/chlorination reaction in step 2?
Date posted:
April 12, 2017
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Answers (1)
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The set u below was used to prepare and collect ethane gas. Study it and answer the questions that follow.
(Solved)
The set u below was used to prepare and collect ethane gas. Study it and answer the questions that follow.
i) Name the substance T.
ii) Give the property of ethane
Date posted:
April 12, 2017
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Answers (1)
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The formula given below represents a portion of a polymer.
(Solved)
The formula given below represents a portion of a polymer.
a) The name of the polymer
b) One disadvantage of continued use of this polymer.
c)Draw the structure of the monomer used to manufacture the polymer.
Date posted:
April 12, 2017
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Answers (1)
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a) The table below gives information about the major constituents of crude oil. Study it and answer the questions that follow.
(Solved)
a) The table below gives information about the major constituents of crude oil. Study it and answer the questions that follow.
i) Which one of the constituents of crude oil has molecules with the highest number of carbon atoms? Explain
ii) Name the process you would use to separate a mixture of petrol and diesel and explain how the separation takes place
iii) Explain why the constituent of crude oil have a range of boiling point.
Date posted:
April 12, 2017
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Answers (1)
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Use the information in the table below to answer the questions that follow. The letters do not represent the actual symbols of the elements
(Solved)
Use the information in the table below to answer the questions that follow. The letters do not represent the actual symbols of the elements
a) Give reasons why the melting point of:
(i) S is higher than that of R;
(ii) V is lower than of U.
b) How does the reactivity of W with chlorine compare with that of R with chlorine? Explain.
c) Write an equation for the reaction between T and excess oxygen.
d) Give one use element V.
Date posted:
April 12, 2017
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Answers (1)
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Use the information in the table below to answer the questions that follow.
(The letters are not the symbols of the elements)
(Solved)
Use the information in the table below to answer the questions that follow.
(The letters are not the symbols of the elements)
Identify a letter which represents an element in the table that could be calcium, carbon or sulphur. Give a reason in each case.
i) Calcium ii) Carbon iii) Sulphur:
Date posted:
April 12, 2017
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Answers (1)
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The grid given below represents part of the periodic table. Study it and answer the questions that follow. The letters do not represent the actual symbols of elements
(Solved)
The grid given below represents part of the periodic table. Study it and answer the questions that follow. The letters do not represent the actual symbols of elements
(i) Select a letter which represents an element that looses electrons most readily. Given a reason for your answer
(ii) Explain why the atomic radius of P is found to be smaller than that of N.
Date posted:
April 12, 2017
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Answers (1)
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Use the information in the table below to answer the questions that follow. The letters do not represent the actual symbols of the elements.
(Solved)
Use the information in the table below to answer the questions that follow. The letters do not represent the actual symbols of the elements.
a) Give reasons why the melting point of:
i) S is higher than that of R;
ii) V is lower than that of U.
b) How does the reactivity of W with chlorine compare with that of R with chlorine? Explain
c) Write an equation for the reaction between T and excess oxygen.
d) Give one use of element V.
Date posted:
April 12, 2017
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Answers (1)
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. The chart below is part of the periodic table. Study it and answer the questions that follow. (The letters are not the actual symbols of the elements)
(Solved)
The chart below is part of the periodic table. Study it and answer the questions that follow. (The letters are not the actual symbols of the elements)
i) Select the element in period three which has the shorter atomic radius. Give a reason for your answer
ii) Element F has the electronic structure, 2.8.18.4. On the chart above, indicate the position of element F.
iii) State one use of the elements of which E is a member.
iv) Write an equation to show the action of heat on the nitrate of element C.
Date posted:
April 12, 2017
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Answers (1)
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The set-up below was used to prepare hydrogen gas
(Solved)
The set-up below was used to prepare hydrogen gas
a) Write an equation for the reaction which takes place when hydrogen gas burns in air
b) State two industrial uses of hydrogen gas
Date posted:
April 12, 2017
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Answers (1)
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The set up shown below was used to investigate a property of hydrogen gas
(Solved)
The set up shown below was used to investigate a property of hydrogen gas
State and explain the observation that would be made in the glass tube if beaker A was filled with hydrogen gas.
Date posted:
April 12, 2017
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Answers (1)
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The graph below shows the relationship between pressure and temperature of a gas in a fixed volume container.
(Solved)
The graph below shows the relationship between pressure and temperature of a gas in a fixed volume container.
a) State the relationship between pressure and temperature that can be deduced from the graph.
b) Using kinetic theory, explain the relationship shown in the graph.
Date posted:
April 12, 2017
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Answers (1)
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The graph below shows the behavior of a fixed mass of a gas at constant temperature.
(Solved)
The graph below shows the behavior of a fixed mass of a gas at constant temperature.
a) What is the relationship between the volume and the pressure of the gas?
b) 3 litres of oxygen gas at one atmosphere pressure were compressed to two atmospheres at constant temperature. Calculate the volume occupied by the oxygen gas
Date posted:
April 12, 2017
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Answers (1)