Question

What is the molar mass of lead (II) chloride $(PbC{l_2})$?

Answer 1

Hint: Molar mass is the same as molecular weight which is literally the weight of each molecule within the compound. To determine the molar mass, add the atomic masses (atomic weights) of each atom present in the molecule. With the help of the masses found in the Periodic Table, calculate the atomic mass of each element.

Complete answer:
We are required to calculate the molar mass of the compound – Lead (II) Chloride.
For this, we first need to establish its molecular formula that is: $PbC{l_2}$
Now the simplest way to find the molar mass of $PbC{l_2}$, is to know the atomic weight of the individual elements present in the molecular formula. We can take a look at the periodic table to find the atomic weight of any element or we can memorize common atomic weights, like that of chlorine.
The first element of $PbC{l_2}$ is $Pb$, its atomic weight as per the periodic table is $Pb = 207.2\;gmo{l^{ - 1}}$
The second element in $PbC{l_2}$ is $Cl$, its atomic weight from the periodic table is $Cl = 35.45\;gmo{l^{ - 1}}$
But keep in mind that if more than one atom of an element exists in the molecular formula, then we must not forget to multiply the atomic weight of that element into the total number of atoms of that element that is present in the compound.
Here we have two atoms of chlorine present so the weight of $C{l_2} = 2 \times 35.45 = 70.9\;gmo{l^{ - 1}}$
Finally the molar mass is the sum of the total weights of all the atoms present in the given compound so the molar mass of lead (II) chloride can be found as follows:
Molar mass of Lead (II) Chloride $ = 207.2\;gmo{l^{ - 1}} + 70.90\;gmo{l^{ - 1}}$
Molar mass of Lead (II) Chloride $ = 278.1\;gmo{l^{ - 1}}$
Therefore the required molar mass is $278.1\;gmo{l^{ - 1}}$.

Note:
The inorganic chloride, lead (II) chloride is made up of two chlorine atoms that are covalently bound to a single lead atom. Lead(II) chloride is a crystalline substance that possesses no colorlessness. It is not easily dissolvable in water. But it does dissolve easily in chloride-ion-containing solutions. Lead(II) chloride can produce lead (II) oxide on reaction with molten sodium nitrite.