Question

What is the molar mass of copper (II) chloride?

Answer 1

Hint: Molar mass of any compound is the measure of the sum of the atomic masses of all the elements present in respective quantities in that compound or substance. The molecular weight is measured in grams per mole. It is the weight of any atom in 1 mole that is $6.022\times {{10}^{23}}$ particles of that atom. So it is measured in g/mol.

Complete answer:
Molecular mass of any molecule is the sum of atomic mass of the individual atoms present in that molecule that can be calculated from the molecular formula of any compound. We have been given to find the molar mass of copper (II) chloride.
 Copper (II) chloride is formed by the transfer of electrons from copper to chloride atom. Therefore it is an ionic compound. It is formed as Cl needs 1 electron to complete its fully filled configuration, and copper is in the valency of +2 here, that means 2 chlorine atoms of -1 charge will be needed to form copper (II) chloride, so the formula of copper (II) chloride is $CuC{{l}_{2}}$ , this means the sum of atomic mass of 1 copper atom and 2 chlorine atoms will give its molar mass.
Atomic mass of copper is 63.546 g/mol and that of chlorine is 35.45 g/mol, so the molar mass of copper (II) chloride will be:
Atomic mass of [(Cu) + 2(Cl)] = [63.546 + 2 (35.45)] g/mol
Molar mass of $CuC{{l}_{2}}$= 134.446 g/mol
So, the molar mass of copper (II) chloride is 134.446 g/mol.

Note:
As copper is a transition element and transition elements having variable oxidation states so, a roman numeral beside their name represents their valency in which they are found in that compound. The molar mass of any substance in grams is measured in grams per mole, also as ‘u’ that stands for unified mass and denotes gram per mole.