What is decreasing order of ionic character of BeCl2 mgcl2 BaCl2 CaCl2?

Ionic character of any molecule depends on the size of cation, anion and on the charges of cation and anion.

In the given example we are provided with same anion so the size and charge of the anion is same in all the cases i.e. Cl^-.

Now consider the cations they all are alkaline earth metals having +2 charge so here also charge is same in every case.

So the only thing which we need to consider is the size of cation. As we know as we move down the group size of atoms goes on increasing. So here the increasing order of size is:

Be, Mg, Ca, Ba

Now according to Fajan's rule

Larger the size of cation and smaller the size of anion favours ionic character in molecules.

Ionic Character of a compound increases with the increase in Lattice energy….

Ionic charecter of a bond is the strength of the force holding ions in place.Lattice energy is the heat required fro breaking up the bond.The more negative the lattice energy, the stronger the force of attraction.

Hope it helps!:)

Be2+(Aq) + 2OH- (aq) = Be(OH)2 (s)

MgCl2 is an ionic compound because this compound is formed by transfer of electrons between magnesium atom and chlorine atoms.

Magnesium atom loses two electrons to form magnesium cation where as each chlorine atom accepts one electron to form chloride ion (anion).

An electrostatic force of attraction works between the oppositely charged ions, that is cation and anion, there by forming an ionic compound.

Note: In an ionic compound, number of electrons lost is always equal to number of electrons gained.

I think RbCl Have more Ionic Character as The Ionic Character depends on Electronegativity of the Elements.The Electronegativity difference between Rubidium and chlorine is more so it will be more Ionic than other three compounds.The Order of decreasing Ionic Character is

RbCl>LiCl>MgCl2>BeCl2

We can conclude that , percentage of Ionic Character is directly propotional to Electronegativity of the Element

Sure - for example the Pauling’s equation.

% I.C. = [1-e^(d.el/2)^2]*100

d.el. = difference of electronegativity

There are other ways, of course, for example measuring the bond dipole moment and comparing it with the theoretical moment of a completely ionic bond.

BaCl2>SrCl2>CaCl2>MgCl2>BeCl2

Hint: for same anion, increase in the size of cation increase in ionic character.

According to Fajan’s Rule, the cation which possesses more +ve charge on it, tends tends to polarise the adjacent anion more, hence enhancing it’s covalent character.

In this case CaCl2, is more covalent than KCl or the converse.

The ability to lose electrons (metals) or gain them (non-metals) and the behavior it exhibits while doing that.