The equation used to represents the electron gain enthalpy is
X(g) + e- → X-(g)
X(s) + e- → X-(g)
X(g) → X+(g) + e-
X(s) → X+(g) + e-
An element in +2 oxidation state has 24 electrons. The atomic number of the element and the number of unpaired electrons in it respectively are
24 and 4
26 and 4
24 and 2
26 and 5
B.
26 and 4
26Fe = 1s2, 2s2 2p6, 3s2 sp6, 4s2, 3d6
26Fe → 26Fe2+
Hence, atomic number of iron (Fe) is 26 and Fe2+ have 4 unpaired electrons in 3d-orbital.
Number of bonding electron pairs and number of lone pairs of electrons in ClF3, SF4, BrF5 respectively are
3, 2, 4, 2, 5, 2
3, 1, 4, 1,5, 2
3, 1, 4, 2, 5, 1
3, 2, 4, 1, 5, 1
Match the following
List I | List II |
(A) Viscosity | (I) Critical temperature |
(B) Ideal gas behaviour | (II) Isobar |
(C) Liquefaction of gases | (III) Compressibility factor |
(D) Charles'law | (IV) kg s-2 |
(V) kgm-1s-1 |
The correct answer
A-IV, B-III, C-I, D-II
A-V, B-III, C-I, D-II
A-V, B-III, C-II, D-I
A-IV, B-III, C-II, D-I
Acccording to significant figure convention the result obtained by adding 12.11, 18.0 and 1.012 is
31.12
31.1
31
31.122