Problem 17 - Chemistry Matter and Change

Question

Describe the separation technique that could be used to separate each of the following mixture. \begin{equation} \begin{array}{l}{\text { a. two colorless liquids }} \\ {\text { b. a nondissolving solid mixed with a liquid }} \\ {\text { c. red and blue marbles of the same size and mass }}\end{array} \end{equation}

Step-by-Step Solution

Answer

a. Distillation; b. Filtration; c. Manual sorting.

Step 1: Separating two colorless liquids

To separate two colorless liquids, we often use the technique of **distillation**. This method relies on the differences in boiling points of the liquids. By heating the mixture, the liquid with the lower boiling point evaporates first, and the vapor is then condensed back into a liquid in a separate container. This way, you separate the two liquids based on their boiling point differences.

Step 2: Separating a nondissolving solid from a liquid

For a nondissolving solid mixed with a liquid, **filtration** is the effective separation method. In this technique, the mixture is poured through a filter, which allows the liquid to pass through while retaining the solid particles. The filter can be made of paper, cloth, or any material with appropriate pores that block the solid particles.

Step 3: Separating red and blue marbles of the same size and mass

To separate marbles, like red and blue marbles of the same size and mass, use the technique of **manual sorting**. This relies on visual identification and physical separation using hands or a device, where red and blue are differentiated by color rather than physical properties like size or mass.

Key Concepts

Distillation

Distillation is a separation technique used to separate liquids based on their boiling points. It is particularly useful when dealing with a mixture of two colorless liquids. The process begins by heating the liquid mixture, which causes the liquid with the lower boiling point to evaporate first.
This vapor is then captured and cooled in a condenser, turning it back into a liquid state. This resulting liquid is collected in a separate container, effectively separating it from the other liquid.

• It is crucial to ensure that the liquids have significantly different boiling points for distillation to be effective.
• The apparatus needed includes a heat source, a condenser, and a collection flask for the distilled liquid.

Understanding the basic principles of distillation can help in practical applications, such as purifying drinking water or separating essential oils. The main idea is to make use of thermal energy to induce phase changes with precision, making distillation a valuable technique in both industrial and laboratory settings.

Filtration

Filtration is a widely used method to separate a solid from a liquid when the solid is nondissolving. This technique is based on size exclusion, where a filter medium is used to allow only the liquid to pass through while trapping the solid particles.
Common materials for filtration include filter paper, cloth, or mesh, which have pores small enough to hold back solid impurities.

• This technique is simple and effective for everyday purposes such as making coffee, where the grounds are separated from the liquid.
• Filter selection is essential to ensure that the pores are appropriate for the size of the solids being filtered out.

Filtration is not only practical for household tasks but is also crucial in scientific laboratories and various industries where purity and separation of components are necessary for product specifications.

Manual Sorting

Manual sorting is an elementary technique used to separate items based on easily identifiable attributes such as color, shape, or texture. In the case of separating marbles of different colors, such as red and blue, manual sorting is a straightforward approach.
The process involves observing the items and physically segregating them by hand or using a simple tool.

• This technique is effective when dealing with solid objects that have distinguishing features discernible by the naked eye.
• It does not require complex equipment or technology, making it accessible and cost-effective.

It is worth noting that while manual sorting is highly feasible for small-scale tasks or when distinguishing characteristics are clear, it can become labor-intensive and impractical for larger quantities or less obvious differences. Nonetheless, it remains a valuable method for simple classification tasks.