Question

A solution is labeled "0.121 M AlCl_" How many moles of chloride ion would be contained in \(1.00 \mathrm{L}\) of the solution?

Short answer

In a 1.00 L solution of 0.121 M AlCl\(_3\), there are 0.363 moles of chloride ions present. To find this, we first determined the moles of AlCl\(_3\) in the solution (0.121 mol) and then used the mole ratio between AlCl\(_3\) and Cl\(^-\) ions (1:3) to calculate the moles of chloride ions.

Step-by-step solution

Find moles of AlCl\(_3\)

Given the concentration of AlCl\(_3\), 0.121 M, and the volume of the solution, 1.00 L, we can determine the moles of AlCl\(_3\) present in the solution by using the following equation: Moles of solute = Concentration × Volume Moles of AlCl\(_3\) = 0.121 M × 1.00 L

Calculate the moles of AlCl\(_3\)

Now we need to calculate the moles of AlCl\(_3\) in the given solution: Moles of AlCl\(_3\) = 0.121 mol/L × 1.00 L = 0.121 mol

Find the moles of Cl\(^-\) ions

In one molecule of AlCl\(_3\), there are three Cl\(^-\) ions. So, to find the moles of Cl\(^-\) ions, we'll use the mole ratio between AlCl\(_3\) and Cl\(^-\): Mole ratio: 1 AlCl\(_3\) : 3 Cl\(^-\) Now we multiply the moles of AlCl\(_3\) by the mole ratio to find the moles of Cl\(^-\) ions. Moles of Cl\(^-\) ions = Moles of AlCl\(_3\) × (3 moles of Cl\(^-\) / 1 mole of AlCl\(_3\))

Calculate the moles of Cl\(^-\) ions

Calculating the moles of Cl\(^-\) ions: Moles of Cl\(^-\) ions = 0.121 mol × (3/1) = 0.363 mol So, in 1.00 L of the 0.121 M AlCl\(_3\) solution, there are 0.363 moles of chloride ions present.

Key concepts

Mole Ratio

When solving chemical problems, understanding the concept of the mole ratio is essential. The mole ratio is a proportion that comes from the coefficients of a balanced chemical equation. It tells us how many molecules or moles of one substance are needed to react with or produce a certain number of molecules or moles of another substance.

For example, in the compound aluminum chloride (AlCl\(_3\)), the formula indicates that one mole of AlCl\(_3\) contains three moles of chloride ions (Cl\(^-\)).

• This is derived from the formula, where the subscript '3' next to Cl indicates there are three chlorine atoms, or ions, per formula unit of AlCl\(_3\).
• Thus, the mole ratio between AlCl\(_3\) and Cl\(^-\) is 1:3.

By understanding mole ratio, chemical calculations become clearer and straightforward. You can easily convert between moles of different substances, knowing how they relate in a reaction or compound, which is useful in determining quantities such as the number of ions.

Moles Calculation

Calculating moles in a chemical solution involves understanding the relationship between concentration, volume, and moles. To find out how many moles there are in a solution, you use the formula:

• Moles = Concentration × Volume.

In our example, we have a 0.121 M solution of AlCl\(_3\). The unit 'M' stands for molarity, which means moles per liter. With a volume of 1.00 L, the calculation becomes straightforward:

Moles of AlCl\(_3\) = 0.121 mol/L × 1.00 L = 0.121 mol

This tells us there are 0.121 moles of AlCl\(_3\) in one liter of this solution. Understanding these fundamentals forms the basis for further calculations, like determining the moles of ions produced in a solution, which is key in various chemical analyses and reactions.

Aluminum Chloride

Aluminum chloride, with the chemical formula AlCl\(_3\), is a compound consisting of aluminum and chlorine. It is often used in chemical processes and reactions and is commonly found in both its solid state and as a solution in laboratories.

In solutions, AlCl\(_3\) is known for fully dissociating, or breaking apart, into its constituent ions. Specifically, when dissolved, it splits into one aluminum ion (Al\(^{3+}\)) and three chloride ions (Cl\(^-\)). This dissociation is crucial when calculating the concentration of ions in a solution.

• For instance, in a 0.121 M solution of AlCl\(_3\), each liter contains not just 0.121 moles of AlCl\(_3\), but also 0.363 moles of Cl\(^-\) ions due to the 1:3 mole ratio.
• This behavior is important in various applications, from chemical synthesis to water treatment processes.

Understanding how AlCl\(_3\) dissociates helps in predicting the behavior of solutions and in stoichiometric calculations, which are essential for precise outcomes in chemical experimentation and industrial applications.