Which of the following sets of qunatum numbers correct?
n =5, l=4, m=0, s=+1/2
n= 3, l=3, m=+3, s= +1/2
n=6, l=0, m=+1, s= =1/2
n=4, l= 2, m=+2, s=0
The pair of elements having approximately equal ionisation potential is
Al, Ga
Al, Si
Al, Mg
Al, B
Water is well known amphoprotic solvent. In which chemical reaction water is behaving as a base?
H2SO4 + H2O → H3O+ + HSO
H2O + H2O → H3O+ + OH-
H2O + NH → NH3 + OH-
H2O + NH3 → NH + OH-
2.5 L of NaCl solution contain 5 moles of the solute. What is the molarity ?
5 M
2 M
2.5 M
12.5 M
The entropy of a perfectly crystalline material is zero at 0°C. This is statement of
first law of thermodynamics
second law of thermodynamics
third law of thermodynamics
law of conservation of energy
C.
third law of thermodynamics
(a) First law of thermodynamics states that energy can neither be created nor be destroyed but one form of energy can be converted into another.
(b) Second law of thermodynamics states that for a spontaneous process in an isolated
system, the change in entropy is positive.
(c) Third law ofthermodynamics states that the entropy of a perfectly crystalline substance is zero at 0°C.
(d) Law of conservation of energy states that energy can neither be created nor be destroyed.
Hence, the given statement is third law of thermodynamics.
When a metal atom combines with a non-metal atom, the non-metal atom will
lose electrons and decrease in size
lose electrons and increase in size
gain electrons and decrease in size
gain electrons and increase in size