This problem aims to find the **mole ratio** of a chemical reaction involving three **chemical substances.**

To better understand the problem, you should know about the **mole, mole weight, **and **mole ratios** in **stoichiometric** reactions. A **stoichiometric chemical reaction** is a reaction in which the combined quantities of the reactants and products are in such a manner that all of the reactants are devoured and not a single mole remains after the fulfillment of the chemical reaction. The **study of stoichiometry** is valuable for estimating chemical reactions such as those that appear in decay processes.

**Mole ratio** is used to analyze the conversion of compounds in a chemical reaction, which is derived from the coefficients that the compounds hold in a balanced chemical equation. Thus, we can say that the mole ratio is used to transform quantities of compounds in a balanced chemical reaction.

**Coefficients** of either reactants or products, in a chemical equation, can be termed as the number of moles of that particular compound.

For example, this reaction: $ N_2 + 3H_2$ $ –> $ $2NH_3$ can be interpreted as:

$1$ mol of nitrogen $+$ $3$ mols of hydrogen yield $2$ mols of ammonia.

## Expert Answer

**Mole ratio** lets us relate moles of reactants to the moles of products using the **coefficients.**

That was all of the explanation, now coming onto the actual answer to the problem:

As per the question,** three-mole ratios** can be noted, implicating three substances. It relies on the constant value of your **reactant** versus your **product.** It also relies on the requested mole ratio. As we know, the mole ratio is the ratio between the quantities in moles of any two or more substances implicated in a chemical reaction.

So it can be defined by approximating the coefficients of a balanced chemical equation, which is also known as a **molar ratio** or **mole-to-mole ratio**.

Consequently, a chemical reaction involving $3$ substances will have a mole ratio of $3$. But as per the **formula of mole-ratio** for a reaction i.e. $n(n-1)$ where $n$ is the number of substances in a reaction, the total mole-ratio comes out to be:

\[ = 3 (3-1) \]

\[ = 3 (2) \]

## Numerical Result

\[ Mole Ratio = 6 \]

Since there are a total of $3$ substances, a total of $6$ **mole ratios** can be written.

## Example

How many mole ratios can be written for a chemical reaction involving $5$ substances?

As per the question, there are **five-mole ratios** for five substances, so it can be defined by approximating the **coefficients** of a **balanced chemical equation.**

Thus, a chemical reaction involving $5$ substances will have a mole ratio of $5$. But as per the formula of mole-ratio for a reaction i.e. $n(n-1)$, the **total mole-ratio** comes out to be:

\[ = 5 (5-1) \]

\[ = 5 (4) \]

\[ Mole Ratio = 20 \]

Since there are a total of $5$ substances, a total of $20$ **mole ratios** can be written.