Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.
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Question 41: The flame used by welders in cutting metals is
Options:
A) butane gas flame
B) acetylene flame
C) kerosene flame
D) oxy-acetylene flame
E) oxygen flame
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The correct answer is D .
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Question 42: An elements X with relative atomic mass 16.2 contains two isotopes 168X with relative abundance of 90% and m8X with relative abundance of 10%. The value of m is
Options:
A) 16
B) 18
C) 12
D) 14
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The correct answer is B .
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Question 43:
200 cm3 of air was passed over heated copper in a syringe several times to produce copper (II) oxide.
When cooled, the final volume of air recorded was 158cm3. Estimate the percentage of oxygen in the air?
Options:
A) 31%
B) 27%
C) 21%
D) 19%
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The correct answer is C .
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Question 44: The correct order of increasing boiling points of the following compounds C3H7OH, C7H16 and C4H10 is
Options:
A) C3H7OH → C4H10 → C7H10
B) C4H10 → C7H16 → C3H7OH
C) C7H16 → C3H7OH → C4H10
D) C4H10 → C3H7OH → C7H16
Show Answer
The correct answer is D .
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Question 45: Two metallic ions associated with hard water are
Options:
A) copper and zinc
B) magnesium and silver
C) calcium and magnesium
D) potassium and tin
E) sodium and lead
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The correct answer is C .
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Question 46: A liquid that will dissolve fat is
Options:
A) Hydrochloric acid
B) Calcium hydroxide
C) Kerosene
D) Water
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The correct answer is B .
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Question 47: Geometric isomerism can exist in
Options:
A) hex-3-ene
B) hexane
C) prop-l-ene
D) 3-methyl but -l-ene
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The correct answer is A .
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Question 48:
What is the IUPAC name for the following compound? HCCCH
Options:
A) Acetylene
B) Methyl acetylene
C) Butanol
D) Decanoic acid
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The correct answer is B .
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Question 49: The basicity of CH3COOH is
Options:
A) 1
B) 2
C) 3
D) 4
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The correct answer is A .
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Question 50: Helium atoms are chemically unreactive because
Options:
A) there are no electrons around the nucleus
B) the number of protons equals the number of electrons
C) there are equal number of protons and neutrons in the nucleus
D) the outer electron shell is completely filled
E) the atoms contain only protons
Show Answer
The correct answer is D .