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 301:
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 302: In the purification of impure samples of ethyl ethanoate synthesized by esterification, concentrated sodium trioxocarbonate (IV) solution is used to remove
Options:
A) water
B) basic impurities
C) acidic impurities
D) ethoxyethane
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The correct answer is C .
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Question 303: A certain liquid has a high boiling point. It is viscous, non-toxic, miscible with water being very hygroscopic. This liquid is most likely to be?
Options:
A) CH3CH2CH2HO
B) CH3CHOHCH3
C) CH3CH2CHOHCH3
D) CH2OHCHOHCH2OH
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The correct answer is D .
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Question 304: Terylene is synthesized from ethane- 1, 2-diol and benzene - 1, 4-dicarboxylic acid by?
Options:
A) addition reaction
B) condensation reaction
C) elimination reaction
D) substitution reaction
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The correct answer is B .
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Question 305: A particle that contains 9 protons, 10 neutrons and 10 electrons is a
Options:
A) negative ion
B) positive ion
C) neutral atom of non-metal
D) neutral atom of a metal
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The correct answer is A .
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Question 306:
H3PO4(aq) + H2O(l) ↔ H2PO4-(aq) + H3O+(aq)
ΔH = -13kJ at 298K
In the reaction above, an increase in temperature would
Options:
A) slow downthe reverse reaction
B) have no effect on the reaction
C) favour the reverse reaction
D) favour the forward reaction
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The correct answer is C .
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Question 307: 1.0 dm3 of distilled water was used to wash 2.0g of a precipitate of AgCl. If the solubility product of AgCl is 2.0 * 10-10mol2dm-6, what quantity of silver was lost in the process?
Options:
A) 2.029 * 10-3mol dm-3
B) 1.414 * 10-3mol dm-3
C) 2.029 * 10-5mol dm-3
D) 1.414 * 10-5mol dm-3
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The correct answer is D .
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Question 308: Which of the following represents an aromatic compound?
Options:
A) C6H5OH
B) C6H12
C) C6H9OH
D) C6H8
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The correct answer is A .
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Question 309: The pOH of a solution of 0.25 mol dm-3 of hydrochloric acid is
Options:
A) 12.40
B) 13.40
C) 14.40
D) 14.60
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The correct answer is B .
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Question 310:
How many electrons will be found in the nucleus of an atom with mass number 23 and 17 neutrons?
Options:
A) none
B) 6
C) 7
D) 8
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The correct answer is A .