What is the value of electron gain enthalpy of Na if IE1 of Na = 5.1 eV?
-5.1 eV
-10.2 eV
+2.55 eV
+10.2eV
Assertion (A): K, Rb and Cs form superoxides.
Reason (R): The stability of the superoxides increases from 'K' to 'Cs' due to decrease in lattice energy.
The correct answer is
Both (A) and (R) are true and (R) is the correct explanation of (A).
Both (A) and (R) are true but (R) is not the correct explanation of (A)
(A) is true but (R) is not true
(A) is not true but (R) is true
Which one of the following order is correct for the first ionisation energies of the elements?
B <Be <N < O
Be <B <N < O
B <Be <O <N
B <O <Be <N
Ce4+ is stable. This is because of
half-filled d-orbitals
all paired electrons ind-orbitals
empty orbital
fully filled d-orbital
Fool's gold is
Cu2S
FeS2
Al2O5
CuFeS2
B.
FeS2
Iron pyrite, FeS2 is also known as fool's gold.