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Question 2:
Write equations for the reactions of
(i) iron with steam
(ii) calcium and potassium with water
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Question 3:
Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.
Metal | Iron (II) sulphate | Cooper (II) sulphate | Zinc sulphate | Silver nitrate |
A. | No reaction | Displacement | ||
B. | Displacement | No reaction | ||
C. | No reaction | No reaction | No reaction | Displacement |
D. | No reaction | No reaction | No reaction | No reaction |
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Question 4:
Which gas is produced when dilute hydrochloric acid is added to a reactive metal? Write the chemical reaction when iron reacts with dilute H2SO4.
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Question 5:
What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes place.
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Question 1:
(i) Write the electron-dot structures for sodium, oxygen and magnesium.
(ii) Show the formation of Na2O and MgO by the transfer of electrons.
(iii) What are the ions present in these compounds?
Page No. 55:
Question 1:
Metallic oxides of zinc, magnesium and copper were heated with the following metals.
Metal | Zinc | Magnesium | Copper |
Zinc oxide | - | - | - |
Magnesium oxide | - | - | - |
Copper oxide | - | - | - |
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Question 2:
Which of the following methods is suitable for preventing an iron frying pan from rusting?
(a) Applying grease
(b) Applying paint
(c) Applying a coating of zinc
(d) all of the above.
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Question 5:
You are given a hammer, a battery, a bulb, wires and a switch.
(a) How could you use them to distinguish between samples of metals and non-metals?
(b) Assess the usefulness of these tests in distinguishing between metals and non-metals.
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Question 8:
In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
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Question 9:
Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below.
(a) What will be the action of gas on
(i) dry litmus paper?
(ii) moist litmus paper?
(b) Write a balanced chemical equation for the reaction taking place.
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Question 15:
A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?
