Question

How many grams are there in the following?
(1) 1 mole of chlorine molecule, $C{{l}_ {2}} $
(2) 2 moles of sulphur molecules, ${{S}_ {8}} $
(3) 4 moles of ozone molecules, ${{O}_ {3}} $
(4) 2 moles of nitrogen molecules, ${{N}_ {2}} $

Answer 1

Hint: In order to convert the mole of substance to grams we will be using the formula: number of moles = given mass / molar mass. As we have been provided with the moles of the substance.

Complete Solution :
We have been provided with 1 mole of chlorine molecule, ($C{{l}_ {2}} $), 2 moles of sulphur molecules, (${{S}_ {8}} $)
 4 moles of ozone molecules, (${{O}_ {3}} $) and 2 moles of nitrogen molecules, (${{N}_ {2}} $).
And we need to convert the mole of the substance to grams,

- So, for that we will be using the formula: number of moles = given mass / molar mass,
So, the first one we have: 1 mole of chlorine molecule, $C{{l}_ {2}} $,
So, the molar mass of chlorine molecule, $C{{l}_ {2}} =35.5\times 2$,
Which is equal to: 71g/mol

- Now, keeping these values in the formula: number of moles = given mass / molar mass,
So, from this we will get: Given mass = number of moles $\times $ molar mass,
Keeping the values: given mass = $1\times 71=71g$,

- Now the next one that we have is: 2 moles of sulphur molecules, (${{S}_ {8}} $),
So, the molar mass of sulphur molecules, ${{S}_ {8}} =32\times 8$,
Which is equal to: 256g/mol

- Now, keeping these values in the formula: number of moles = given mass / molar mass,
So, from this we will get: Given mass = number of moles $\times $ molar mass,
Keeping the values: given mass = $2\times 256=512g$,
The next one is: 4 moles of ozone molecules, (${{O}_ {3}} $),
So, the molar mass of ozone molecules, ${{O}_ {3}} =3\times 16$,
Which is equal to: 48g/mol

- Now, keeping these values in the formula: number of moles = given mass / molar mass,
So, from this we will get: Given mass = number of moles $\times $ molar mass,
Keeping the values: given mass = $4\times 48=192g$,
The last one is: 2 moles of nitrogen molecules, ${{N}_ {2}} $,
So, the molar mass of nitrogen molecules, ${{N}_ {2}} =2\times 14$,
Which is equal to: 28g/mol

- Now, keeping these values in the formula: number of moles = given mass / molar mass,
So, from this we will get: Given mass = number of moles $\times $ molar mass,
Keeping the values: given mass = $2\times 28=56g$,
so, we have changed all the given moles of the substance into grams.
So, the correct answer is “Option B”.

Note: Molar mass is of great importance when setting up an experiment. If you are testing principles involving specific amounts of a substance, the molar mass allows you to figure out how much you should weigh out on your scale.