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 731: Calculate the relative molecular mass of Limestone CaCO3, (Ca = 40, C =12, O = 16)
Options:
A) 56
B) 100
C) 76
D) 90
Show Answer
The correct answer is B .
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Question 732: Which of the gases is employed as an anaesthesia?
Options:
A) N 2O
B) NO2
C) NH3
D) NO
Show Answer
The correct answer is A .
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Question 733: The ratio of the initial to final pressure of a given mass of gas is 1:1.5. Calculate the final volume of the gas if the initial volume was 300 cm3 at the same temperature
Options:
A) 120 cm3
B) 200 cm3
C) 450 cm3
D) 750 cm3
Show Answer
The correct answer is B .
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Question 734: The experiment that showed that atoms have tiny positively charged nucleus was first carried out by
Options:
A) Moseley
B) Rutherford
C) Millikan
D) Dalton
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The correct answer is B .
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Question 735: A gas jar was inverted over burning yellow phosphorus floating over water in a beaker. After burning, the water level was found to rise in the gas jar. The water level rises because
Options:
A) pressure inside the gas jar is greater than pressure outside it
B) the air in the gas jar had been used up by burning
C) oxygen in the gas jar had been used up by burning
D) nitrogen in the gas jar had been used up by burning
E) the temperature in the jar had risen considerably
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The correct answer is C .
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Question 736:
In the extraction of iron, hot air is introduced into the blast furnacethrough?
Options:
A) valves
B) open-hearths
C) arcs
D) tuyeres
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The correct answer is D .
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Question 737: When a little brine was added to a metal nitrate a white precipitate was formed which first turned violet and then black on exposure to ai. The metal nitrate is therefore?
Options:
A) sodium nitrate
B) mercuric nitrate
C) lithium nitrate
D) silver nitrate
E) potassium nitrate
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The correct answer is D .
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Question 738:
A small quantity of solid ammonium chloride (NH4Cl) was heated gently in a test tube, the solid gradually disappears to produce two gases. Later, a white cloudy deposit was observed on the cooler part of the test tube. The ammonium chloride is said to have undergone
Options:
A) distillation
B) sublimation
C) precipitation
D) evaporation
E) decomposition
Show Answer
The correct answer is B .
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Question 739: Three liquids X, Y and Z containing only hydrogen and carbon were burnt on a spoon. X and Y burnt with sooty flames while Z did not. Y is able to discharge the colour of bromine water whereas X and Z cannot. Which of the liquids would be aromatic in nature?
Options:
A) X and Z
B) Y
C) X
D) Z
Show Answer
The correct answer is B .
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Question 740:
If the quantity of oxygen occupying 2.76L container at a pressure of 0.825 atm and 300k is reduced by one-half, what is the pressure exerted by the remaining gas?
Options:
A) 1.650atm
B) 0.825atm
C) 0.413atm
D) 0.275atm
Show Answer
The correct answer is A .