Chapter 13, Problem 13.151P

(a)

Interpretation Introduction

Interpretation:

The empirical formula of urea is to be calculated.

Concept introduction:

The empirical formula of a chemical compound is the simplest positive integer ratio of the atoms that are present in the compound. It may or may not be the same as that of the molecular formula. For example, the empirical formula of sulfur dioxide is $\text{SO}$.

(b)

Interpretation Introduction

Interpretation:

The molar mass and molecular formula of urea is to be calculated.

Concept introduction:

The osmotic pressure is defined as the measure of the tendency of a solution to take in pure solvent via osmosis. It is defined as the minimum pressure that is to be applied to the solution to prevent the inward flow of the pure solvent across the semipermeable membrane. Osmosis occurs when two solutions have different concentrations of solute and are separated by a semipermeable membrane.

The formula to calculate the osmotic pressure of the solution is as follows:

$\prod =MRT$ (4)

Here, $\prod$ is the osmotic pressure.

$M$ is the molarity of the solution.

$R$ is universal gas constant.

$T$ is the absolute temperature.

Molarity is defined as the number of moles of solute that are dissolved in one litre of solution. It is represented by $M$ and its unit is $\text{mol/L}$.

The formula to calculate the molarity of the solution is as follows:

$\text{Molarity}=\frac{\text{amount}\left(\text{mol}\right)\text{of}\text{solute}}{\text{volume }\left(\text{L}\right)\text{of}\text{}\text{solution}}$ (5)

The conversion factor to convert $°\text{C}$ to ${}^{°}\text{K}$ is as follows:

$T\left({}^{°}\text{K}\right)=T\left({}^{°}\text{C}\right)+273.15\text{K}$