Chapter 13, Problem 13.20QP

Interpretation Introduction

Interpretation:

The molarity and molality of the given acid solution which is $\text{98\%}$ mass percent of ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ should be calculated.

Concept introduction:

Molarity: The concentration for solutions is expressed in terms of molarity as follows,

$\text{Molarity = }\frac{\text{No}\text{. of moles of solute}}{\text{Volume of solution in L}}$

Molality: Molality is defined as number of moles of the solute present in the specified amount of the solvent in kilograms.

$\text{Molality =}\frac{\text{number of moles of the solute}}{\text{kg of solvent}}$

Percent by mass: It is the ratio of solute mass to the solution mass which finally multiplied by $\text{100}$. The formula for percent by mass calculation is as follows,

$\begin{array}{l}\text{Percent mass =}\frac{\text{Mass}\text{of}\text{solute}}{\text{Mass of solution}}\text{×100\%}\\ \text{Mass of solution = Mass of solute + Mass of solvent}\end{array}$

Moles: One mole is equivalent to the mass of the substance consists same number of units equal to the atoms present in $\text{12}\text{g}$ of ${}^{\text{12}}\text{C}$.

From given mass of substance moles could be calculated by using the following formula,

$\text{Moles}\text{of}\text{substance }\text{= }\frac{\text{Given}\text{mass}\text{of}\text{substance}}{\text{Molecular}\text{mass}}$

Mass: It is the quantitative measure of a substance. The amount of matter present in substance is expressed as mass. The $S.I.$ unit of mass is $kg$.

Density is calculated by mass of the substance divided by its volume.

$\text{density =}\frac{\text{mass}}{\text{volume}}$