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 691:
10.0 dm3 of air containing H2S as an impurity was passed through a solution of Pb(NO3)2 until all the H2S had reacted. The precipitate of PbS was found to weigh 5.02 g. According to the equation: Pb(NO3)2 + H2S → PbS + 2HNO3 the percentage by volume of hydrogen sulphide in the air is?
(Pb = 207, S = 32, GMV at s.t.p = 22.4dm3)
Options:
A) 50.2
B) 47.0
C) 4.70
D) 0.47
Show Answer
The correct answer is C .
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Question 692: Which of the following samples will react fastest with dilute trioxonitrate (V) acid?
Options:
A) 5 g of lumps of CacO3 at 25°C
B) 5 g of powered CacO3 at 25°
C) 5 g of lumps of CaCO3 at 50°C
D) 5 g of powered CaCO3 AT 50°C
Show Answer
The correct answer is D .
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Question 693: The shapes of CO, HO and CH respectively are
Options:
A) bent, linear and tetrahedral
B) bent, tetrahedral and linear
C) linear, bent and tetrahedral
D) tetrahedral, linear and bent
Show Answer
The correct answer is C .
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Question 694:
Use the graph above to answer this question.How long does it take all the solid to melt?`
Options:
A) 2.5 mins
B) 6.0 mins
C) 1.0 min
D) 3.0 mins
Show Answer
The correct answer is A .
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Question 695:
Which of the following is a common property of non-metals?
Options:
A) Exist as solids at room temperature
B) Tend to gain electrons in chemical reactions
C) High thermal conductivity
D) Readily form cations in chemical reactions
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The correct answer is B .
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Question 696: Which of the following equimolar solutions will have the highest pH?
Options:
A) CH3COOHa
B) NaOH
C) HCl
D) NH4OH
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The correct answer is B .
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Question 697: 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 698: Kerosine is commonly used to remove the red colour stain of palm oil from cloths because it
Options:
A) helps to spread the oil over a larger surface area
B) react with the oil to form an odourless compound
C) makes the oil evaporate easily by dissolving it
D) helps to dilute the oil and reduce its colour
Show Answer
The correct answer is C .
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Question 699: There are basic particles from which matter called be made except
Options:
A) Salt
B) Atom
C) Ion
D) Molecule
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The correct answer is A .
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Question 700:
How many pi () bonds are there in an alkene with six carbon atoms?
Options:
A) 4
B) 6
C) 5
D) 3
Show Answer
The correct answer is D .