Chapter 9, Problem 1CE

Interpretation Introduction

Interpretation:

The ratio that is same as the coefficients present in a balanced chemical equation is to be predicted.

Concept introduction:

The stoichiometry of a chemical species involved in a chemical reaction represents the number of chemical species involved in the chemical reaction. The stoichiometry of a chemical species is also calculated by using a number of moles.

Answer to Problem 1CE

The ratio of coefficients of the stoichiometry present in the reaction is equals to the moles of gas and the volume of gas but is not equal to the mass of gas

Explanation of Solution

Consider a reaction between A and B to form C.

$\text{A}+\text{B}\to \text{C}$…(1)

In the above reaction, $1\text{mol}$ of A reacts with $1\text{mol}$ of B. The coefficients of both A and B are $1$. This shows that the ratio of the coefficients of the stoichiometry present in the reaction is equals to moles of gas.

The formula to determine molarity is shown below.

$M=\frac{\text{n}}{\text{V}}$

Where

• $M$ is the molarity of a solution.

• $\text{n}$ is the number of moles of solute.

• $\text{V}$ is the volume of the solution.

Rearrange the above equation as shown below.

$\text{V}=\frac{\text{n}}{M}$

The above relation shows that the volume of gas is directly proportional to the number of moles of a gas. Therefore, the number of moles of a gas in the equation (1) is same for A, B and C. This means the ratio of the coefficients of the stoichiometry present in the reaction is equals to the volume of gas.

The formula to determine the number of moles is shown below.

$\text{n}=\frac{\text{Given}\text{mass}\text{of}\text{substance}}{\text{Molar}\text{mass}\text{of}\text{substance}}$

Rearrange the above equation as shown below.

$\text{Molar}\text{mass}\text{of}\text{substance}=\frac{\text{Given}\text{mass}\text{of}\text{substance}}{\text{n}}$

The above relation shows that the mass of a substance is dependent on the molar mass of a substance. The molar mass of every substance is different. Therefore, the ratio of coefficients of the stoichiometry present in the reaction is not equal to the mass of gas.

Conclusion

The ratio of coefficients of the stoichiometry present in the reaction is equals to the moles of gas and the volume of gas.