Question

The mass of $5$ moles of ${{H}_{2}}S{{O}_{4}}$ is:
(A) $180g$
(B) $250g$
(C) $300g$
(D) $490g$

Answer 1

We know that molecular mass is the sum of individual atoms in the molecule. Start the question by writing the chemical formula of sulphuric acid and then add the molar mass of individual atoms. Split the given condensed form of the compound. By doing this you can identify the different atoms present in the compound.

Complete answer:
Now write the mass of each atom and the total sum of the masses will be the resultant molar mass. Sulphuric acid is composed of sulphur, oxygen and hydrogen. Sulfuric acid is a mineral acid with the element composition of sulphur, oxygen and hydrogen. It is also called the oil of vitriol. It is highly corrosive in nature towards other materials including the human skin. Sulphuric acid exists as a colourless viscous liquid having no odour at room temperature. It is synthesized in reactions that are extremely exothermic i.e. release a lot of energy. We will now break down the formula of sulphuric acid to identify constituent atoms.
The chemical formula of Sulphuric acid is given as ${{H}_{2}}S{{O}_{4}}.$ As we can see from the chemical formula given above, Sulphuric acid has two atoms of hydrogen, one atom of Sulphur and four atoms of oxygen.
The molar mass of hydrogen is $1$ ; Molar mass of sulphur $\left( S \right)$ is $32$ ; Molar mass of oxygen $\left( O \right)$ is $16$ .
Now, $2\left( 1 \right)+32+4\left( 16 \right)\text{ }=\text{ }98$
Thus, Molar mass of sulphuric acid i.e. ${{H}_{2}}S{{O}_{4}}~$ is $98.$
Therefore, $98g$ for $1$ mole, Hence for $5$ moles $5\times 98=490g$ .

Note:
Remember that sulphuric acid is a very strong acid. It is diprotic, i.e. it can release two protons in an aqueous solution. It is a very strong oxidizing agent and it reacts with metals at high temperature. It is also a very strong and efficient dehydrating agent. It finds use in various industries, such as petroleum refining, wastewater processing etc.