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 481: Which of the following mixtures would result in a solution of pH greater than 7?
Options:
A) 25.00 cm3 of 0.05 M H2SO4 and 25.00cm3 of 0.50 M Na2CO3
B) 25.00 cm3 of 0.05 M H2SO4 and 25.00 cm3 of 0.10 M NaHCO3
C) 25.00 cm3 of 0.11 MH2SO4 and 25.00cm3 0. 10 M NaOH
D) 25.00cm3 of 0.11 MH2 SO4 and 50.00 cm3 of 0.05 M NaOH
E) 25.00cm3 of 0.25 M H2SO4 and 50.00cm3 of 0.20 M NaOH
Show Answer
The correct answer is A .
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Question 482: A phenomenon where an element exist in different forms in the same physical state is known as
Options:
A) isomerism
B) amorphism
C) allotropy
D) isotopy
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The correct answer is C .
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Question 483: An element that can exist in two or more different structural forms which possess the same chemical properties is said to exhibit.
Options:
A) polymerism
B) isotopy
C) isomorphism
D) isomerism
E) allotrophy
Show Answer
The correct answer is E .
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Question 484:
Calculate the pH of 0.05 moldm HSO
Options:
A) 1.30
B) 1.12
C) 1.00
D) 0.30
Show Answer
The correct answer is A .
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Question 485:
An element used in the production of matches is
Options:
A) nitrogen
B) aluminium
C) copper
D) sulphur
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The correct answer is D .
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Question 486:
The presence of ammonia gas in a desiccator can exclusively be removed by
Options:
A) phosphorus (V) oxide
B) fused calcium chloride
C) calcium chloride
D) concentrated tetraoxosulphate (VI) acid
Show Answer
The correct answer is D .
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Question 487: 25 cm3 of 0.02 M KOH neutralized 0.03 g of a monobasic organic acid having the general formula CnH2n + 1 COOH. The molecular formula of the acid is?(C = 12, H = 1, O = 16)
Options:
A) HCOOH
B) C2H5COOH
C) CH3COOH
D) C3H7COOH
Show Answer
The correct answer is C .
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Question 488: Due to the high reactivity of sodium, it is usually stored under
Options:
A) water
B) mercury
C) paraffin
D) phenol
Show Answer
The correct answer is C .
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Question 489: 2SO2(g) + O2(g) 2SO3. In the reaction above, the standard heats of formation of SO2(g) and SO3(g) are -297 KJ mol-1 respectively. The heat change of the reaction is?
Options:
A) -99 kJ mol-
B) -198 kJ mol-
C) +198 kJ mol-
D) +683kJ mol-
Show Answer
The correct answer is B .
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Question 490: A substance S is isomorphous with another substance R. When a tiny crystals of S is added into a supersaturated solution of R?
Options:
A) S dissolves in the solution
B) crystals of R are precipitated
C) there is no observable change
D) R and S react to generate heat
Show Answer
The correct answer is B .