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 51: Ethene is prepared industrially by
Options:
A) Reforming
B) Polymerization
C) Distillation
D) Cracking
Show Answer
The correct answer is D .
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Question 52: Which of the additives could improve the quality of steel?
Options:
A) Silicon
B) Sulphur and phosphorus
C) Carbon
D) Chromium and nickel
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The correct answer is D .
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Question 53: The dissolution of common salt in water is a physical change because
Options:
A) the salt can be obtained by crystallization
B) the salt can be recovered by the evaporation of water
C) heat is not generated during mixing
D) the solution will not boil at 100oC
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The correct answer is C .
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Question 54: Which of the following statements is NOT true of electrovalent compounds?
Options:
A) They are solids
B) They do not vaporized easily
C) They usually dissolve in water
D) The elements forming the compounds normally have their valency electrons in a shared state
E) They conduct electricity
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The correct answer is D .
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Question 55: Which of the following solutions will conduct the least amount of electricity?
Options:
A) 2.00 M aqueous solution of NaOH
B) 0.01 M aqueous solution of NaOH
C) 0.01 M aqueous solution of hexanoic acid
D) 0.01 M aqueous solution of sugar
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The correct answer is D .
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Question 56:
What weight of NaCl is needed to make 2.0 dm3 of a 1.5M solution?
[Na = 23, Cl = 35.5]
Options:
A) 116 g
B) 175 g
C) 87 g
D) 58 g
Show Answer
The correct answer is B .
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Question 57:
CU2S(s) + O2(g) → 2CU(s) + SO2(g)
What is the change in the oxidation number of copper in the reaction above?
Options:
A) +1 to 0
B) 0 to +2
C) +2 to +1
D) 0 to +1
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The correct answer is A .
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Question 58: Which of the following compounds can be represented by the molecular formula C2 H6O?
Options:
A) propanal
B) ethanol
C) methanoic acid
D) glucose
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The correct answer is B .
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Question 59: 300 cm3 of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume
Options:
A) 243.75 cm3
B) 369.23 cm3
C) 738.46 cm3
D) 1733.36 cm3
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The correct answer is B .
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Question 60: The fuming of kettles is caused by the presence in the water of
Options:
A) calcium tetraoxosulphate (IV)
B) calcium hydrogentrionocarbonate (IV)
C) calcium hydroxide
D) calcium trioxocarbonate (IV)
Show Answer
The correct answer is B .