IGCSE Chemistry Paper-1: Specimen Questions with Answers 42 - 44 of 99
Question number: 42
Question
The diagrams show the arrangement of particles in three different physical states of substance X.
Which statement about the physical states of State A and State C is correct?
Three States of the Matter
Understanding the 3 different states of the matter
Choices
| Choice (4) | Response | |
|---|---|---|
| a. | State A changes to state C by Freezing |
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| b. | State A changes to State C by Melting. |
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| c. | State A changes to State C by vaporization |
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| d. | State A changes to state C by Deposition |
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Answer
a.Explanation
The above three figures clearly state that Figure 1 is a liquid substance, Fig 2 is a gas and Fig 3 is a solid.
Therefore it can be seen that a liquid state is changing to a solid state.
Freezing is the process by which a liquid state changes to solid state.
Question number: 43
Question
On moving down in group in periodic table which one of the following does not increase?
Choices
| Choice (4) | Response | |
|---|---|---|
| a. | Valence |
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| b. | Atomic radius |
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| c. | Metallic character |
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| d. | No of shells |
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Answer
a.Explanation
The elements in the same group going from top to down have the same kind of electronic configuration. Consider in group 1 from top to bottom,
H = 1
Li = 2,1
Na = 2,8, 1
And so on.
We can see that the valence electron number remains the same as we move down in a group.
Question number: 44
Question
Which bond is not in a molecule of ethanoic acid?
Choices
| Choice (4) | Response | |
|---|---|---|
| a. | C = C |
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| b. | C–O |
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| c. | O–H |
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| d. | C = O |
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Answer
a.Explanation
The structural formula of ethanoic acid is:
Structure of Ethanoic Acid
Ethanoic acid structure with no carbon - carbon double bond
From the above structure it is clear that there is no C = C bond.