Multiple Choice QuestionsPumice is the name of the most common volcanic rock that floats. It has various air bubbles and capillaries which trap air. Which statement is correct for this rock
Air cavities are interconnected
Air cavities are not connected
Density of rock is more than water
Rock is very older
B.
Air cavities are not connected
Pumice is an igneous rock. It consists of a specific gravity of less than one and can float on water. The vesicles are gas bubbles trapped inside it. The material in it cools so quickly that atoms in the melt are not able to arrange themselves into a crystalline structure. Thus, making it an amorphous volcanic glass known as mineraloid.
The correct configuration for given structure is :
L-configuration
D-configuration
R-configuration
S-configuration
High Biological Oxygen demand in water body indicates
Chemical pollution
Organic pollutant
High photoautotroph
Pressure of heterotrophs
What amount has to be taken from 11 N HCl to make 50 mL of 2N HCl :
11.0 mL
9.09 mL
6.03 mL
2.0 mL
If a reactangle is inscribed in circle of diameter 'D'. Then the area of rectangle will be:
Independent of length and breadth
Will be always smaller than D2/2
Will be always smaller than D2/4
Will be always greater than D2/4
Which of the following element is required for production of thyroxin?
NaCl
Iodine
Bromine
Fluorine
Temperature above which gas cannot be liquified even by applying pressure is termed as-
Critical temperature
Boyle temperature
Curie temperature
Charles temperature
If a nail is hammered in the bark of tree at height 4 m, after ten years the height of tree is doubled. Then the height of nail will be:
4 m
8 m
16 m
10 m
Lassaigne's test is employed to detect the presence of nitrogen, sulphur, halogens and phosphorus in an organic compound. These elements are present in the covalent form in an organic compound. On treatment with sodium metal covalent carbon of organic compound are converted into which ionic forms:
Cyanide
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Nitrate
Carbide
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