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 501: CxHY + 4O2 → 3CO2 + 2H2O. The hydrocarbon, CxHY, in the reaction above is?
Options:
A) propane
B) propene
C) propyne
D) propanone
Show Answer
The correct answer is C .
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Question 502: Calculate the amount in moles of silver deposited when 9650C of electricty is passed through a solution of silver salt [= 96500 Cmol-1]
Options:
A) 0.05
B) 10.80
C) 10.00
D) 0.10
Show Answer
The correct answer is D .
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Question 503:
RS(aq) + HF(aq) → RF(s) + HS(aq)
ΔH = -65.7 kj mol(-1).
From the equation above, it can be deduced that
Options:
A) the heat content of the reactants is lower than that of the products
B) the heat content of the reactants is higher than that of the products
C) the reaction is slow
D) a large amount of heat is absorbed
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The correct answer is B .
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Question 504: An organic compound contains 72% carbon, 12% hydrogen and 16% oxygen by mass. The empirical formula of the compound is
Options:
A) C8H22O3
B) C6H10O3
C) C12H12O
D) C6H12O
E) C3H6O
Show Answer
The correct answer is D .
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Question 505: The formula for ethyl butanoate is
Options:
A) C3H7COOC2H5
B) C2H5COOC3H7
C) C4H9COOC2H5
D) C2H5COOC4H9
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The correct answer is A .
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Question 506: A small quantity of solid ammonium chloride (NH4Cl) texted gently in a test tube, the solid gradually disappear produce two gases. Later, a white cloudy deposit was absence on the cooler part of the test tube. The ammonium chloride is to have undergo
Options:
A) distillation
B) sublimation
C) precipitation
D) evaporation
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The correct answer is B .
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Question 507:
Alkanes are used mainly?
Options:
A) in the textile industry
B) in the hydrogenation of oils
C) as domestic and industrial fuels
D) as fine chemicals
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The correct answer is C .
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Question 508: Potassium vapour burns with a
Options:
A) blue flame
B) brick-red flame
C) violet flame
D) golden-yellow flame
Show Answer
The correct answer is C .
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Question 509:
Which of the following alkaline metals react more quickly spontaneously with water?
Options:
A) Calcium
B) Beryllium
C) Magnesium
D) Strontium
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The correct answer is A .
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Question 510:
A colored gas that is known to be poisonous and can readily damage the mucous liningof the lungs is?
Options:
A) hydrogen sulphide
B) carbon(ii)oxide
C) chlorine
D) sulphur(iv)oxide
Show Answer
The correct answer is C .