Which of the following gives correct arrangement of compounds involved based on their bond strength ?
HF > HCl > HBr > HI
HI > HBr > HCl > HF
HF > HBr > HCl > HI
HCl > HF > HBr > HI
The enthalpy of combustion at 25°C of H2, cyclohexane (C6H12) and cyclohexene (C6H10) are -241, -3920 and -3800 kJ/mol respectively. The heat of hydrogenation of cyclohexene is :
-121 kJ/mol
+121 kJ/mol
-242 kJ/mol
+242 kJ/mol
The entropy values (in JK-1mol-1) of H2 (g) = 130.6, Cl2 (g) = 223.0 and HCl (g) = 186. 7 at 298 K and 1 atm pressure. Then entropy change for the reaction :
H2 ( g)+ Cl2 (g) 2HCl (g) is:
+540.3
+727.3
-166.9
+19.8
A certain sample of gas has a volume of 0.2 L measured at 1 a:tm pressure and 0°C. At the same pressure but 273°C, its volume will be :
0.4 L
0.8 L
27.8 L
55.6 L
When electrons are trapped into the crystal in anion vacancy, the defect is known as :
Schottky defect
Frenkel defect
stoichiometric defect
F-centres
By which one of the following compounds both CH4 and CH3 - CH3 can be prepared in one step?
CH3I
CH3OH
CH3CH2I
C2H5OH
R - NH - COH Product
In the given reaction, what will be the product?
R - N = C = O
R - C-
R - C N
None of these
Which of the following is secondary pollutant?
CO2
N2O
PAN
SO2
C.
PAN
Pollutants which are formed by reaction amongst the primary pollutants are called as secondary pollutants e.g., peroxyacyl nitrates (PAN) are formed through reaction between nitrogen oxides and hydrocarbons in the presence of sunlight.