D and F block Flashcards
what are transition metals
metals who have partially filled d orbital are transition metals
what are D block elements
the elements whose ultimate electron enters d orbital
which group elements are not transition metals
Group 12
what is Group 12 in Mendeleevs table known as
II B
name some properties of transition metals
1 Can act as catalyst
2 Paramagnetic (due to unpaired electrons)
3 very high MP and BP
Name some transition metals which have very low MP and BP
Zinc
Cadmium
Mercury
Why group 12 elements have very low MP and BP
Due to completly filled D orbital
Less electron involved in bonding
When going from 4d to 5d atomic size almost remains same . Why?
due to poor shielding of 4f orbital
What is Lanthanoid contraction
the filling of 4f before 5d orbital results in regular decrease in atomic radii called Lanthnaoid contraction
why transition metals have high density
decrease in metallic radius with increase in atomic mass results in increase in density
On what factors ionisation enthalpy depends on
attraction of electron by nucleus
repulsion between electron
Exchange energy (depends on no of parallel spin)
why the ionisation enthalpy of Mn + smaller than Cr +
because electron removed in Mn is not taking part in exchange
what is common oxidation state of transition metals
+2
Why transition metals shows variable valency
due to incomplete filling of d orbital
which metal has negative Eo vlaue
Copper (cannot liberate H+ from acids )
which metal forms trihalide
Magnesium(ONLY)
Why flourine is more stable with higher oxidation states
due to higher lattice energy
why Cu+2 is more stable than Cu+
Cu +2 has more negative hydration enthalpy hence it compensates for ionisation enthalpy of Cu
Define ferromagnets
substance which are attracted very strongly are said to be ferromagnets
What is d-d transition
electron present in lower energy d orbital absorbs energy and goes higher energy d orbital it is called d-d transition
what are interstitial compounds
interstitial compounds are those which are formed when small compounds like H C or N are trapped inside the crystal lattices of metals
Name some properties of intertitial compounds
high MP
very hard
metallic conductivity
chemically inert
What are alloys
Homogenous solid solution in which the atoms of one metal is distributed randomly among the atoms of the other
Example
brass = Copper + Zinc
bronze = copper + tin
what is the color of K2MnO4
Green
what is the color of MnO2
black
What is common oxidation state of lanthanoids
+3
What is CAN test
it stands for cerric ammonium nitrate test
Used to detect the presence of alcohol
properties of lanthanoids
silvery white color
soft metals
tranish rapidly in air
Which lanthanoid is the hardest
Samarium
which metal has the lowest oxidation potential
Europium
due to 4f 7
What is mischmetall
Iron + lanthanoid metal
Actnoid contractions is greater than lanthanoid contraction WHY
5f orbitals have a poorer shielding effect than 4f
What is Ziengler catalyst
TiCl4 + AL(CH3)3
used in production of polythenes
What is Wacker process
oxidation of ethyne to ethanal in presence of PdCl2
