In a reaction, A + B C + D, D, 40% of B has reacted at equilibrium, when 1 mole of A was heated with 1 mole of B in a 10 L closed vessel. The value of Kc is
0.44
0.18
0.22
0.36
If the ionc product of Ni(OH)2 is 1.9× 10-15, the molar solubility of Ni(OH)2 in 1.0 M NaOH
1.9 × 10-18 M
1.9 × 10-13 M
1.9 × 10-15 M
1.9 × 10-15 M
Which one of the following elements on doping with germanium, make it a p-type semiconductor?
Boron
Selenium
Arsenic
Germanium
What are X and Y in the following reaction?
CF2Cl, Cl
C2F4, Cl2
CFCl2, F
CCl2, F2
A.
CF2Cl, Cl
Since, chlorofluorocarbon compounds, i.e , freons (CFCs) are non-reactive, non-inflamable, non-toxic organic molecules, these are widely used in air conditioner, refrigerators, in electronic industry for cleaning computer parts. Due to very long life time (CF2Cl2-12 '139 years, CFCl3-11 77 years), these compounds ultimately react the stratosphere where they get broken down by powerful UV radiations and release chlorine free radical. The chlorine free radicals react with ozone and cause its depletion.
Temporary hardness of water is removed in Clark's process by adding
caustic soda
calgon
borax
lime
Which one of the following correctly represents the variation of electronegatrvity (EN) with atomic number (Z) of group 13 elements?
Which one of the following is more readily hydrolysed by SN1 mechanism?
(C6H5)2C(CH3)Br
C6H5CH2Br
C6H5CH(CH3)Br
(C6H5)2CHBr