Question

What is the formula mass of methylene chloride \[C{{H}_{2}}C{{l}_{2}}\] ?

Answer 1

Hint: We know that the answer to this question depend on the concept of the formula mass and the molar mass calculation using the definitions that sum of atomic mass of all the atoms in formula unit gives formula mass and the quantity of the substance is the molar mass in \[gram/mol.\]

Complete answer:
In the classes of basic concepts of chemistry from the previous chapters, we have come across some of the basic concepts like the empirical formula calculation, molecular formula calculation, formula mass, molar mass and also many other terms. Let us now see the calculation of molar mass and formula mass according to their definition as ‘the sum of the atomic masses of all the atoms in the formula unit in an ionic crystal’. Molar mass of a substance is defined as the quantity of the substance which is equal to the molecular mass in grams.
Here we have given methylene chloride\[~C{{H}_{2}}C{{l}_{2}}\] which is also known as methylene dichloromethane.
\[{{M}_{C}}=12.01g/mol;~{{M}_{H}}=1.0078g/mol;~{{M}_{Cl}}=\text{ }35.45g/mol~\]all these values are atomic masses of each compounds respectively.
Now by Molar Mass of \[C{{H}_{2}}C{{l}_{2}}=\left[ 12.01+\left( 2\times 1.0078 \right)+\left( 35.45\times 2 \right) \right]=84.93g/mol,\]
Now, the formula mass according to the definition says that the sum of atomic masses of all the units in the given compound will give the formula mass and if we calculate, we get the same answer as above.
Therefore, the formula mass of methylene chloride \[C{{H}_{2}}C{{l}_{2}}\text{ }is\text{ }84.93g/mol.\]

Note:
Remember that the mass is a quantity that gives an idea about how much matter is present in an object. It is a quantitative measure of inertia. So acceleration is inversely proportional to inertia.