1 mole of photon, each of frequency 2500 s-1, would have approximately a total energy of
10 erg
1 J
1 eV
1 MeV
A.
10 erg
Frequency of one photon = 2500 s-1
:. Frequency of 1 mole of photon
= 6.023 x 1023 x 2500 s-1
The second law of thermodynamic says that in a cyclic process
work cannot be converted into heat
heat cannot be converted into work
work cannot be completely converted into heat
heat cannot be completely converted into work
Which of the following will decrease the pH of a 50 mL solution of 0.01 M HCl?
Addition of 5 mL of 1 M HCl
Addition of 50 mL of 0.01 M HCl
Addition of 50 mL of 0.002 M HCl
Addition of Mg
Equal volumes of molar hydrochloric acid 'and sulphuric acid are neutralized by dilute NaOH solution and x kcal and y kcal of heat are liberated respectively. Which of the following is true ?
x = y
x =y/2
x = 2y
none of these
For the Paschen series the values of n1 and n2 in the expression
n1= 1, n2 = 2, 3, 4, ...
n1= 2, n2 = 3, 4, 5,...
n1= 3, n2 = 4,5,6,...
n1= 4, n2 = 5,6,7,...
Under which of the following conditions is the relation valid for a closed system ?
Constant pressure
Constant temperature
Constant temperature and pressure
Constant temperature, pressure and composition
An organic compound made of C, H and N contains 20% nitrogen. Its molecular weight is
70
140
100
65