In the above compounds, Cl– anion is common for all, but cations are different. According to Fajan’s rule, the covalent character in ionic compounds depends on the size of cation, anion and charge of both the cation and anion.
Now,
the cation with smaller size and high charge has higher polarizing power. That
is, they cause polarization of electron charge cloud of an anion to a greater
extent.
Carbon
disulfide is also known as carbon bisulfide, is a neurotoxic colorless volatile
liquid with chemical formula, CS2. The IUPAC name of carbon
disulfide is methane dithione.
Carbon
disulfide is a colorless liquid in purest form and it is light yellow under
impure state. Carbon disulfide has pure chloroform like or ether like odor.
Carbon
black material is also known as
acetylene black, channel black, furnace black, lamp black, and thermal black.
It is a black solid with molar mass 12.01 g/mol. The density of carbon black at 20°C is 1.8-2.1 g/cc.
Sodium
hydrogen carbonate is also name as sodium bicarbonate, is a
chemical compound with molecular formula, NaHCO3. It is also known as an acidic
salt or bi salt, which is made from carbonic acid.
Ammonia water means aqueoussolution of ammonia. Ammonia water is also known as ammonia liquor, aqueous ammonia, ammonium hydroxide, aqua ammonia, ammoniacal liquor etc.
It
is symbolically expressed as NH3 (aq.)
or NH4OH. Ammonia water solution
has fishy and highly pungent smell.
Aqueous ammonia or aqueous solution of ammonia, also
known as ammonia solution, ammonia water, ammonia liquor, ammoniacal liquor,
aqua ammonia and finally ammonium hydroxide, is a solution of ammonia in water.
Ammonia is highly soluble in water. It has been
experimentally found that at 273K temperature, 1000 volume of ammonia gas is
dissolved in 1 volume of water. Because of ammonia molecules form very strong
hydrogen bond with water molecule.
Ammonium carbonate is an inorganic
salt with molecular formula (NH4)2CO3. It is
also known as baker’s ammonia and was a precursor to the more modern leavening
agent baking soda and baking powder.
The molar mass of ammonium carbonate is 96.09 g/mol. It is a colorless crystalline solid or white powder with a strong odor of NH3 and has a sharp ammoniacal taste.
Most of the transition
metal atoms or ions have a common tendency to form complex compoundscomplex ions when they are attached to the neutral molecules [such as CO, NO, NH3, H2O]
or ions [Cl–, CN–,
NO2–].
The above said neutral molecules or ions are called
ligand. One or more atoms in ligand are capable to form co-ordinate bond with
the atoms or ions of transition metal
by sharing of electrons.
Most of the transition metals and their compounds are
used as catalyst in the chemical reaction. They are known for their homogeneous
and heterogeneous catalytic activity.
Transition metal elements exhibit catalytic property
because of their some special characters those are given below.
Most of the compounds of
transition metals are colored in the solid or in the solution states. In the
case of free metal ion, all the five d-orbitals have the same energy. That is,
they are degenerate, meaning energetically alike.
But when a uniformly spread
negative charge or a ligand approaches towards the d-orbitals of the metal
ions, then the electrostatic repulsion between d-electrons and this negative
charge would result in uniform increase in the energies of d-orbitals.
Though, under this condition the five d-orbitals of metal ions would still remain degenerate. Now consider that the negative charge or ligand surrounding d-orbitals of the metal ions gets concentrated in a number of point charges in certain specific positions.
Elements that have partially filled inner (n-1)d
sub-shell in the atomic state or in the permanent oxidation state are called
transition metal elements. Most of the transition elements are metal.
Transition metals become very hard except Zn, Cd and
Hg. They are very much harder than s-block and p-block elements. Generally, transition
metal elements have very high melting point
and boiling point.
The melting points of most of the transition metalselements (except Zn, Cd and Hg) are above 900°C. Their melting point and boiling point are very much higher than s-block
and p-block elements.
The transition metals show very high melting point and boiling point due to the presence of very strong metallic bond as well as covalent bond in their metallic crystal lattice.
Elements
that have a partially filled d-sub-shell in the atomic
state or permanent oxidation state are called transition metals. Generally, d-block elements are known as transition metal elements.
The periodic table contains the transition metals between the s-block and p-block elements. The common electronic configuration of outer most valence shell of transition metal elements are (n-d)1-10 ns1-2 .
The term ‘ionization
energy’ of elements is a very important topic in chemistry. We can know
some important properties of elements from the value or idea of ionization energy.
The ionization
energy or first ionization energy
of an element is defined as the amount of energy required to remove the most
loosely bounded valence electron from an isolated gaseous atom, converting it
into unique positive ion.
Since in this process heat energy is supplied to
remove electron hence it is an endothermic process.
Ionization
energy or first ionization
energy is defined as the minimum amount of energy required to remove the
most loosely bound electron of an isolated neutral gaseous atom, converting
into ion with one unit positive charge.
(Isolated gaseous atom) Ionization energy (Gaseous ion)
Units of ionization enthalpy: Since ionization enthalpy
is related with energy, hence the unit of ionization potential should the same
of energy.
Ionization energy has three types of unit, namely electron volt/atom (eV/atom), kcal/mol, kJ/mol.
Generally, the order of ionization energy decreases when we move from top to button along a
group.
But, in case of group-13 elements, the order of
ionization enthalpy change is not regular. It has been found that the value of ionization energy from B to Al
decreases.
This is because in this case the combined effect of
increasing the size of the atom and the screening effect exceeds the effective
nuclear charge of the atom.
Acid rain literally means
acid rain water. The
pH value of ordinary rainwater is less than 7.But
the pH value of acid rain is between 3.5- 5.6.
This is because non-metallic
acid oxides like SO2, NO2 and CO2 are released into the atmosphere due to
various natural and man-made causes. Again HCl vapor from the HCl producing
plant dissolves in the air.
All of these gaseous elements dissolve in rainwater during precipitation to produce H2SO4, HNO3, H2CO3 and HCl acids and fall to the ground. This is called acid rain.
When some non metallic acidic oxide such as SO2, NO2, CO2 and gaseous HCl etc are mixed with dew, snowfall and rain water, forming sulfuric acid, nitric acid, carbonic acid and hydrochloric acid, come down on the earth from atmosphere, then this phenomenon is called acid rain
Outbreaks of acid rain have been observed in different parts of the world. One of them is America, Canada, Russia, China, India etc. However, the incidence of acid rain is much lower in India.
However, the percent of different acids in acid rain is not specified. The percentage of different acids in acid rain can vary from one place to another place.
However, by examining different samples of
acid rain, an approximate percentage value of different acids in acid rain has
been determined.
It has been experimentally found that, in the creation
of acid rain, the contribution of sulfuric acid is 60-65% and that of for
nitric acid is 30-35%.
The contribution of other acids (such as HCl, H2SO3
and HNO2) those are responsible for acid rains is1-2%.
Percent of acid present in
acid rain, acid rain, contribution of different acids in acid rain, acid rain definition.
Ammonium
sulfate is an inorganic compound with chemical formula, (NH4)2SO4. It is
nitrogen as well as sulfur containing manure and is predominantly used in
agriculture.
Ammonium
sulfate is also known as ammonium tetraoxosulfate, diammonium sulfate, mascagnite,
dolamin, actamaster, sulfuric acid diammonium sulfate etc.
It
is fine white hygroscopic granules or crystals and soluble in water but
insoluble in acetone, ether or alcohol.
The
solubility of ammonium sulfate in water increases with increase in temperature.
The density of ammonium sulfate is 1.76 g/cc and it melts at 508 to 533K.
Urea is a very notable organic
compound with chemical formula CO (NH2)2. Urea is also known as carbonyldiamide, carbamide, carbonyldiamine etc.
Urea is considered as the first organic compound that synthesized by Friedrich Ohler, in 1828, from inorganic compounds, NH4CNO.
It is odorless white solid and highly soluble in water. Solubility in
water, 1.08 g/ml at 293K and solubility increase with increasing temperature.
Urea is also soluble in glycerol and ethanol solvent. The solubility of urea in glycerol is 0.5 g/ml and in ethanol is 0.05 g/ml.
The
density of urea solution is 1.31 g / ml. Melting point range of urea 406K to
408K.
Ammonia
Ammonia and bleach are both inexpensive and effective household cleaners.
Household ammonia is a solution of NH3 in water, and is used as a general purpose cleaner for many surfaces.
Like bleach, ammonia is also an effective household item cleaner. Ammonia is also a
great cleaner.
Approximately
5% to 10% ammonia solution is usually used as
household cleaner.
Household
ammonia is usually 70% water, 30% ammonium hydroxide (H2O + NH4OH). Like bleach, ammonia also acts as a disinfectant
and kills germs.
What is nitric acid (HNO3) in chemistry?
There are seven oxo acids of nitrogen are known. Nitric acid is one of them with molecular formula HNO3. Nitric acid is a highly corrosive mineral acid.
Most
of the metals and non metals are soluble in nitric acid. For this reason, nitric
acid is also known as aqua fortis, its mean ‘strong water’.
Pure nitric acid is a colorless liquid at room
temperature, but older sample of nitric acid may be yellow or reddish brown
color. It is suffocating and also acrid smelling acid.
It is smoked in humid air. The melting point of pure HNO3 is 231K and the boiling point of pure nitric acid is 355.6K.
Paramagnetic and
diamagnetic
character of substance depends on the number of unpaired and paired electrons
occupied by that substance.
Any
substances those contain number of unpaired electrons are called paramagnetic
substances. On the other side, if the substance does not contain any odd
electrons, is called diamagnetic substance.
