The plot of square root of frequency of X-ray emitted against atomic number led to suggestion of which law/rule?
Periodic law
Modern periodic law
Hund's rule
Newland's law
If average velocity of a sample of gas molecules at 300 K is 5 cm s-1, what is RMS velocity of same sample of gas molecules at the same temperature? (Given, α: u: v = 1:1.224: 1.127)
6.112 cm/s
4.605 cm/s
4.085 cm/s
5.430 cm/s
20 mL solution of 0.1 M ferrous sulphate was completely oxidised using a suitable oxidising agent. What is the number of electrons exchanged?
1.204 x 1022
193
1930
1.204 x 1021
The volume of oxygen evolved at STP by decomposition of 0.68 g '20 volume' hydrogen peroxide solution is
2.24mL
22.4mL
224mL
2240mL
What is the molality of a solution containing 200 mg of urea (molar mass 60 g mol-1) dissolved in 40 g of water?
0.0825
0.825
0.498
0.0013
C.
0.498
The work done when two mole of an ideal gas is compressed form a volume of 5 m3 to 1 dm3 at 300 K, under a pressure of 100 kPa is
499.9kJ
-499.9 kJ
-99.5 kJ
42495 kJ
Assuming enthalpy of combustion of hydrogen at 273 K is -286 kJ and enthalpy of fusion of ice at the same temperature to be +6.0 kJ, calculate enthalpy change during formation of 100 g of ice.
+1622 kJ
- 1622 kJ
+292 kJ
- 292 kJ
The product of molar concentrations of hydrogen ions and hydroxide ions in a 0.01 M aqueous solution of sodium chloride is known as
hydrolysis constant of salt
dissociation constant of acid
dissociation constant of base
ionic product of water