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No chemical reaction takes place when granules of a solid A, are mixed with the powder of another solid B
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1
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1137
|
March 29, 2019
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(a) What is meant by corrosion? Name any two methods used for the prevention of corrosion
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1
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4885
|
March 29, 2019
|
|
(a) What is a reactivity series? Describe an activity to develop a reactivity series
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1
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2211
|
March 29, 2019
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(a) What are ionic compounds? List any four physical properties of these compounds
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1
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2340
|
March 29, 2019
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Give reasons for the following: (i) Metals are regarded as electro-positive elements
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1
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2929
|
March 29, 2019
|
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How is an alloy made? List two proposes of making alloys and mention the constituents and two properties of each of the following alloys:
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1
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1373
|
March 29, 2019
|
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Give reasons for the following observations: (i) Ionic compounds in general have high melting and boiling points
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1
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7236
|
March 29, 2019
|
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1. What is an alloy? How does it differ from an amalgam?
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1
|
1480
|
March 29, 2019
|
|
What is meant by ‘rusting’? With labelled diagrams describe an activity to find out the conditions under which iron rusts
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1
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13120
|
March 29, 2019
|
|
(i) Arrange the following metals in decreasing order of their reactivity: Fe, Zn, Na, Cu, Ag
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1
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2058
|
March 29, 2019
|
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(a) Name a metal for each case: (i) It does not react with cold as well as hot water but reacts with steam
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1
|
7174
|
March 29, 2019
|
|
Give reasons for the following: (a) Metals can be given different shapes according to our needs
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1
|
8214
|
March 29, 2019
|
|
Give reasons for the following: (a) Gold and silver are used to make jewellery
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1
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3338
|
March 29, 2019
|
|
What are amphoteric oxides? Choose the amphoteric oxides from amongst the following oxides:
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1
|
16336
|
March 29, 2019
|
|
Explain the following terms by giving one exafhple of each:
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1
|
630
|
March 29, 2019
|
|
Give reasons for the following: (i) Metals are regarded as electro-positive elements
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1
|
947
|
March 29, 2019
|
|
Explain the Froth Flotation?
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1
|
666
|
March 29, 2019
|
|
(a) What would you observe when you put: (i) Some zinc pieces into blue copper sulphate solution?
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1
|
16178
|
March 29, 2019
|
|
Give reasons for the following: (a) Na, K and Ca metals form hydride by combination with hydrogen gas, but most other metals do not
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1
|
4678
|
March 29, 2019
|
|
Give reasons for the following: (a) Zinc oxide is considered as an amphoteric oxide
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1
|
18193
|
March 29, 2019
|
|
Write chemical equations for reactions taking place when:
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1
|
2085
|
March 29, 2019
|
|
Give reason for the following: (a) Silicon counts among metalloids
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1
|
2740
|
March 29, 2019
|
|
(i) How are metalloids different from metals? Name a metalloid
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1
|
1609
|
March 29, 2019
|
|
Write chemical equations for the reactions taking place when: (i) Zinc sulphide is heated in air
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1
|
1456
|
March 29, 2019
|
|
Give reasons for the following: (i) Metals conduct electricity
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1
|
1949
|
March 29, 2019
|
|
(a) What are strategic metals? Give one example also. (b) State the reason for the following behaviour of zinc metal:
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1
|
2186
|
March 29, 2019
|
|
Curd is not kept in copper and brass utensils. Why?
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1
|
2873
|
March 29, 2019
|
|
(a) Distinguish between ionic and covalent compounds in the following properties:
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1
|
835
|
March 29, 2019
|
|
Name the metals which reacts violently with cold water. Write any three observations
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1
|
811
|
March 29, 2019
|
|
Choose the metal (from the list given below) which can displace zinc from zinc sulphate solution
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1
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2825
|
March 29, 2019
|