20257.The Latin word formica means ant. The name formic acid is derived from this Latin word because
this acid, in ancient times, was used to eliminate ant-hills
this corrosive acid is secreted by ants to drive away their enemies
this acid was first obtained by the distillation of ants
ants are attracted by the odour of this acid
20309.The mass number of an atom is equal to
the number of protons
the number of protons and electrons
the number of nucleons
the number of neutrons
20270.The items amenable to detection by soft x-rays are
contrabands
lead in bullets
narcotics
genuine coins from counterfeit coins
20251.The heat required to raise the temperature of body by 1 K is called
specific heat
thermal capacity
water equivalent
None of the above
20286.The high reactivity of fluorine is due to
its high electro negativity
small size of fluorine atom
availability of d-orbitals
strong F - F bond
20261.What are the number of moles of CO2 which contains 16 g of oxygen?
0.5 mole
0.2 mole
0.4 mole
0.25 mole
20274.The gas used in the manufacture of vanaspati from vegetable oil is
hydrogen
oxygen
nitrogen
carbon dioxide
20282.The gas used for artificial ripening of green fruit is
ethylene
ethane
carbon dioxide
acetylene
20276.The graphite rods in the nuclear reactor
react with U to release energy
produce neutrons
undergo combustion which triggers the nuclear fission
convert fast moving neutrons into thermal neutrons
20253.The mass of P4O10 that will be obtained from the reaction of 1.33 gram of P4 and 5.07 of oxygen is
2.05 gram
3.05 gram
4.05 gram
5.05 gram
20252.The nuclear particles which are assumed to hold the nucleons together are
electrons
positrons
neutrons
mesons
20306.The number of atoms present in 21.6 gram of silver (atomic weight = 108) are same as the molecules in
1.8 gram of H2O
12 moles of KMnO4
0.6N H2SO4
4.6 gram of C2H5OH
20313.The method of concentrating the ore which makes use of the difference in density between ore and impurities is called
liquation
leaching
levigation
magnetic separation
20250.The nucleus of a hydrogen atom consists of
1 proton only
1 proton + 2 neutron
1 neutron only
1 electron only