Threshold frequency of a metal is 5 1013 s-1 upon which 1 x 1014s-1 frequency light is focused. Then the maximum kinetic energy of emitted electron is
3.3 10-21
3.3 10-20
6.6 10-23
6.6 10-20
At equilibrium which is correct?
G = 0
S = 0
H = 0
= 0
A.
G = 0
In unfavorable reaction have Delta G values that are positive (also called endergonic reaction). When Delta G for reaction is zero, a reaction is said to be at equilibrium. Equilibrium does not mean equal concentrations. If the Delt G is zero, there is no net change in A and B, as the system is at equilibrium.
Arrange the following gases in order of their critical temperature.
NH3, H2O, CO2, O2
NH3 > H2O > CO2 > O2
O2 > CO2 > H2O > NH3
H2O > NH3 > CO2 > O2
CO2 >O2 >H2O > NH3
Bond dissociation energy of CH4 is 360 kJ/mol and C2H6 is 620 kJ/mol. Then bond dissociation energy of C-C bond is
170 kJ/mol
50 kJ/mol
80 kJ/mol
220 kJ/mol
pKa increases in benzoic acid when substituent "x" is bonded at para-position, then "x" is
-COOH
-NO2
-CN
-OCH3