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 721: An oxide XO2 has a vapour density of 32. What is the atomic mass of X?
Options:
A) 32
B) 20
C) 14
D) 12
Show Answer
The correct answer is A .
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Question 722:
Proteins in acid solution undergo?
Options:
A) Substitution
B) Fermentation
C) Hydrolysis
D) Polymerisation
Show Answer
The correct answer is C .
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Question 723: The approximate volume of air containing 10cm3 of oxygen is?
Options:
A) 20 cm3
B) 25 cm3
C) 50 cm3
D) 100 cm3
Show Answer
The correct answer is C .
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Question 724:
NO(g) + CO(g) ↔ (1)/(2)N2(g) + CO2(g) ∆H = -89.3 kj.
What conditions would favour maximum conversion of nitrogen (II) oxide and carbon (II) oxide in the reaction above?
Options:
A) Low temperature and high pressure
B) High temperature and low pressure
C) High temperature and high pressure
D) Low temperature and low pressure
Show Answer
The correct answer is A .
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Question 725:
Which of the following is a form of calcium carbonate?
I. limestone
II. marble
III. chalk
Iv. egg-shells
Options:
A) I only
B) I, II and IV
C) I and II only
D) I, II, III, and IV
Show Answer
The correct answer is D .
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Question 726:
Which of the following alkaline metals react more quickly spontaneously with water?
Options:
A) Calcium
B) Beryllium
C) Magnesium
D) Strontium
Show Answer
The correct answer is A .
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Question 727: A substance Z reacts with NaOH to give salt and water only. When Z is treated with dilute HCl, a gas is evolved which gives a yellow suspension on passing into concentrated H2SO4. Substance Z is?
Options:
A) NaHS
B) Na2SO3
C) Na2S
D) NaHSO3
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The correct answer is A .
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Question 728: Cellulose and starches can be classified as one of the following?
Options:
A) sugars
B) sucrose
C) hydrocarbons
D) carbohydrates
E) isomers
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The correct answer is D .
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Question 729: When platinum electrodes are used during the electrolysis of copper (ll) tetraoxosulphate (lV) solution, the solution gets progressively?
Options:
A) acidic
B) basic
C) neutral
D) amphoteric
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The correct answer is A .
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Question 730: The hybridization of the carbon atom in ethyne is
Options:
A) sp 4
B) sp 3
C) sp2
D) sp
E) s
Show Answer
The correct answer is D .