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 571:
In the diagram above which of the cures illustrates Arrhenius' law?
Options:
A) Y
B) Z
C) R
D) X
Show Answer
The correct answer is D .
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Question 572:
Given that 15.00 cm3 of H2
SO4 was required to completely neutralize 25.00 cm3 of 0.125 mol dm-3 NaOH, calculate the molar concentration of the acid solution:
Options:
A) 0.925 mol dm-3
B) 0.156mol dm-3
C) 0.104 mol dm-3
D) 0.023 mol dm-3
Show Answer
The correct answer is C .
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Question 573:
If a reaction is exothermic and there is a great disorder, it means that
Options:
A) The reaction is in a state of equilibrium.
B) There will be a large increase in free energy.
C) There will be a large decrease in free energy.
D) The reaction is static.
Show Answer
The correct answer is C .
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Question 574: The greater the different in electronegativity between bonded atoms, the?
Options:
A) lower the polarity of the bond
B) higher the polarity of the bond
C) weaker the bond
D) higher the possibility of the substance formed being a molecule
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The correct answer is C .
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Question 575: COg + H2Og 2g + H2g H = -4100J. Which of the following factors favour the formation of hydrogen in the above reaction? i. high pressure. ii. low pressure iii. high temperature iv. use of excess steam
Options:
A) i, iii and iv
B) iii only
C) ii, iii and i
D) iv only
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The correct answer is D .
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Question 576: Which of the following is NOT an alkali?
Options:
A) NH3
B) Mg(OH)2
C) Ca(OH)2
D) NaOH
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The correct answer is A .
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Question 577:
CO(g) + H2 O(g) → CO2(g) + H2(g)
Calculate the standard heat change of the reaction above, if the standard enthalpies of formation of CO2(g), H2O(g) and CO(g) and CO(g) in KJ mol -1 are - 394 -242 and - 110 respectively.
Options:
A) + 262 KJ mol -1
B) - 262 KJ mol -1
C) + 42 KJ mol -1
D) - 42 KJ mol -1
Show Answer
The correct answer is D .
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Question 578:
2KClO3(g) MNO3→ 2KCl(s) + 3O2(g)
The importance of the catalyst in the reaction above is that
Options:
A) heating may not be required before the reaction takes place
B) the reaction is controllable even at a high temperature
C) the reaction produces large quantity of oxygen
D) the reaction takes place more rapidly at a lower temperature
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The correct answer is D .
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Question 579:
Which of the following are mixtures?
i. Petroleum
ii. Rubber latex
iii. Vulcanizer's solution
iv. Carbon (II) sulphide
Options:
A) i, ii and iii
B) i, ii and iv
C) i and ii only
D) i and iv
Show Answer
The correct answer is A .
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Question 580:
If 30cm3 of oxygen diffuses through a porous pot in 7 seconds, how long will it take 60cm3 of chlorine to diffuse through the same pot, if the vapour densities of oxygen and chlorine are 16 and 36 respectively?
Options:
A) 9.3 sec
B) 14 sec
C) 21 sec
D) 28 sec
E) 30.3 sec
Show Answer
The correct answer is C .