Question

Is the separation method used in brewing a cup of coffee best described as distillation, filtration, or chromatography? \([\) Section 1.3\(]\)

Short answer

The separation method used in brewing a cup of coffee is best described as filtration, as hot water passes through ground coffee beans and through a porous filter, separating the liquid coffee from the solid particles.

Step-by-step solution

Define Distillation

Distillation is a process of separating mixtures based on differences in their volatilities in a boiling liquid mixture. It involves heating the mixture and collecting the vapor that forms, then cooling and condensing the vapor back into a liquid.

Define Filtration

Filtration is a process of separating a solid from a liquid or gas by passing the mixture through a porous medium (such as a filter), which captures the solid particles while allowing the liquid or gas to pass through.

Define Chromatography

Chromatography is a technique used for separating components of a mixture based on their interaction with a stationary phase and a mobile phase. The stationary phase is usually a solid or liquid, while the mobile phase is a liquid or gas.

Compare Brewing Coffee to the Given Separation Methods

When brewing coffee, hot water is passed through ground coffee beans (a mixture of solid particles). The coffee flavor and other soluble components in the beans dissolve in the water, leaving behind the insoluble solid particles. The liquid coffee passes through a porous medium (like a coffee filter) to separate it from the solid particles.

Determine the Best Description for the Separation Method in Brewing Coffee

Comparing the process of brewing coffee to the three separation methods, the method that best describes this process is filtration. This is because during brewing, hot water passes through ground coffee beans and through a porous filter, separating the liquid coffee from the solid particles.

Key concepts

Distillation: A Method of Separation

Distillation is a common technique employed to separate mixtures based on variances in boiling points of the components. This involves heating a liquid mixture until one part vaporizes, capturing the vapor, and then cooling it back into a liquid form. This process is handy for separating substances with significant differences in volatility.

Imagine you have a mixture of water and alcohol. When heated, alcohol vaporizes first due to its lower boiling point compared to water. The alcohol vapor is condensed back into a liquid and collected separately, allowing you to isolate it from the water.

Distillation is extensively used in industries, like:

• Purifying drinking water
• Producing essential oils
• Manufacturing alcoholic beverages

However, since coffee brewing doesn't involve vaporizing and recondensing components, distillation isn't the method used.

Chromatography: An Analytical Technique

Chromatography is an analytical technique used to separate and study components of a complex mixture. It is based on the differential partitioning between a stationary phase and a mobile phase.

In chromatography, the mixture is dissolved in the mobile phase, which moves over the stationary phase. Components of the mixture separate based on their affinities towards the phases, allowing one to isolate and analyze them.

It is commonly used in:

• Chemical analysis and purification
• Identifying substances in forensic science
• Food and beverage quality control

Although chromatography is a powerful technique for separation, it doesn't describe what's happening when coffee is brewed. This is because coffee brewing involves filtering rather than the movement of compounds across phases.

The Coffee Brewing Process: An Example of Filtration

Brewing coffee is an enjoyable ritual that involves the filtration process. When you make coffee, hot water is poured over ground coffee beans. This hot water extracts the soluble aromatic oils, caffeine, and flavors from the coffee grounds.

A filter, such as paper or metal mesh, is then utilized to separate the flavorful liquid from the insoluble grounds. This function of the porous medium effectively captures solid particles while letting the liquid pass through.

Features of filtration involved in coffee brewing:

• Separation of solid particles (coffee grounds) from liquid (brewed coffee)
• Using a barrier (coffee filter)
• No need for heat beyond the initial water heating and no phase change involved

Thus, the coffee brewing process exemplifies filtration, showing how straightforward yet effective this method can be for separating components.