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 111: Steam changes the colour of anhydrous cobalt (II) chloride from
Options:
A) blue to pink
B) white to red
C) white to green
D) blue to white
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The correct answer is A .
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Question 112: The oxidation number of manganese in KMnO4 is?
Options:
A) +1
B) +3
C) +5
D) +7
E) +2
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The correct answer is D .
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Question 113: The number of isomers that can be obtained from 04R0 is
Options:
A) 3
B) 4
C) 1
D) 5
E) 2
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The correct answer is E .
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Question 114: Chlorine gas is prepared in the laboratory by
Options:
A) adding concentrated hydrochloric acid to solid manganese (IV) oxide
B) aciding concentrated tetraoxosulphate (VI) acid to solid sodium chloride
C) dropping concentrated hydrochloric acid onto potassium tetraoxomanganate (VI) crystals
D) aciding concentrated tetraoxosulphate (VI) acid to hydrochloric acid
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The correct answer is A .
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Question 115:
How many valence electrons are contained in the element ?
Options:
A) 3
B) 4
C) 15
D) 31
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The correct answer is A .
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Question 116: Which of the following is a neutralization reaction? Addition of
Options:
A) nitric acid to hydrochloric acid
B) nitric acid to sulphuric acid
C) nitric acid to distilled water
D) nitric acid to sodium hydroxide
E) sodium chloride to distilled water
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The correct answer is D .
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Question 117:
Which of the following statements is correct about the periodic table?
Options:
A) Elements in the same period have the same number of valence electrons
B) The valence electrons of the elements in the same period increase progressively across the period
C) Elements in the same group have the same number of electron shells
D) The non-metallic Properties of the elements tend to decrease across each period
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The correct answer is B .
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Question 118: When a solid substance disappears completely as a gas on heating, the substance is said to have undergone
Options:
A) evaporation
B) distillation
C) crystallization
D) sublimation
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The correct answer is D .
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Question 119:
SO + O 2SO
In the reaction above, the most suitable catalyst is?
Options:
A) chromium(vi)oxide
B) iron(iii)oxide
C) copper(i)oxide
D) vanadium(v)oxide
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The correct answer is D .
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Question 120: If y is an oxidizing agent that reacts with a reducing agent, Z, which of the following is correct?
Options:
A) Y increases in oxidation number
B) Y becomes reduced
C) Z loses protons
D) Z gains protons
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The correct answer is B .