20273.The inexpensive and commonly used variety of glass is called soda glass. It is called so because
was used initially for making bottles of soda(carbonated drink)
is made using soda(sodium carbonate)
was initially used for storing sodium carbonate
is made using soda lime
20280.The method that cannot be used for removing permanent hardness of water is
adding sodium carbonate
distillation
adding caustic soda
boiling
20290.The main chemical constituent of clay is
silicon oxide
aluminium borosilicate
zeolites
aluminium silicate
20265.The number of water molecules present in a drop of water (volume 0.0018 ml) at room temperature is
1.568 x 103
6.023 x 1019
4.84 x 1017
6.023 x 1023
20301.The hottest part of the gas flame is known as
luminous zone
dark zone
blue zone
non-luminous zone
20288.The ionisation energy of hydrogen atom in the ground state is x KJ. The energy required for an electron to jump from 2nd orbit to 3rd orbit is
5x/36
5x
7.2 x
x/6
20284.The main chemical constituent of the oil of cardamom which is responsible for flavour of this oil is
cineole
engenol
geraniol
limonene
20264.The luster of a metal is due to
its high density
its high polishing
its chemical inertness
presence of free electrons
20260.The heat energy produced when the human body metabolises 1 gram of fat is
30 KJ
1 KJ
39 KJ
29 KJ
20275.The ionic radii of N3-, O2-, F- and Na+ follows the order
N3- > O2- > F- > Na+
N3- > Na+ > O2- > F-
Na+ > O2- > N3- > F-
O2- > F- > Na+ > N3-
20302.The human body is made up of several chemical elements; the element present in the highest proportion (65%) in the body is
carbon
hydrogen
oxygen
nitrogen