Question

Describe the method, which can be used to separate two compounds with different solubilities in a solvent \(\mathrm{S}\).

Short answer

Use filtration: dissolve the mix in solvent, filter out insoluble compound, and collect the soluble compound by evaporating the solvent.

Step-by-step solution

Understand the Problem

We need to separate two compounds based on their differing solubilities in a solvent. This implies that one compound dissolves in the solvent while the other does not.

Choose an Appropriate Method

The ideal method to separate compounds with different solubilities is 'filtration'. This technique allows the separation of a soluble compound from an insoluble compound.

Prepare the Mixture

Mix the two compounds in the solvent \(\mathrm{S}\), allowing the one that is soluble to dissolve, while the insoluble compound remains undissolved.

Perform the Filtration

Use a filter setup to separate the mixture. Pour the mixture onto the filter paper in a funnel. The insoluble compound will remain on the filter paper, while the soluble compound will pass through with the solvent as the filtrate.

Collect the Soluble Compound

To isolate the soluble compound from the filtrate, evaporate the solvent. This can be done by letting the solvent evaporate naturally or by applying heat, leaving behind the dissolved compound.

Key concepts

Solubility

Solubility is a fundamental concept in chemistry that refers to the ability of a substance to dissolve in a solvent. It is influenced by several factors, such as temperature, pressure, and the nature of the solvent and solute. In the context of separating compounds, solubility becomes a key parameter. When two substances are mixed together, their differing solubility can be leveraged to separate them effectively.

• If a compound is soluble in a given solvent, it will dissolve and form a solution.
• If it is insoluble, it will remain in a separate phase, often as a solid that can be removed.

Understanding the solubility helps in selecting the right separation technique.

Filtration

Filtration is a popular method used to separate a soluble compound from an insoluble one. It involves pouring a mixture through a filter medium that allows only certain particles to pass.

• This process utilizes a funnel and filter paper to catch solid particles that do not dissolve.
• The liquid that passes through, known as the filtrate, contains the dissolved solute.

Filtration is very effective for large particles or when precise separation is needed. In our exercise, once the soluble compound is dissolved in the solvent, the undissolved solid is left behind on the filter paper, facilitating easy separation.

Evaporation

Evaporation is used to remove the solvent from the solution leaving behind the soluble compound. This technique is simple but important in the separation process. It works on the principle that different substances have different boiling points.

• By applying heat, the solvent evaporates, transforming from liquid to vapor, while the soluble compound remains as a residue.
• This technique can be accelerated by increasing the temperature or reducing the pressure over the solution.

Evaporation is a key step after filtration to recover the dissolved compound in a pure form.

Compound Separation

Compound separation is a critical process in chemistry and industry. It aims to isolate desired compounds from mixtures using their chemical and physical properties, such as solubility and melting point. The overarching goal is to obtain useful components in pure form, free from unwanted impurities.

• Common separation techniques include distillation, centrifugation, and chromatography, but filtration and evaporation are fundamental and widely applicable, as illustrated in our exercise.
• These methods vary based on the specific compounds involved and the desired purity level of the final product.

By employing such methods, efficiency and accuracy in chemical processes are significantly enhanced.