Question

Distillation and filtration are important methods for separating the components of mixtures. Suppose we had a mixture of sand, salt, and water. Describe how filtration and distillation could be used sequentially to separate this mixture into the three separate components.

Short answer

To separate a mixture of sand, salt, and water into its individual components, first, use filtration to remove sand by pouring the mixture through filter paper placed in a funnel. The sand will be left on the filter paper, and the saltwater solution will be collected in a beaker below. Next, use distillation to separate salt and water. Pour the saltwater solution into a round-bottom flask in a distillation apparatus and heat it. Water will evaporate and condense in the condenser, collecting in a flask. After distillation, collect the remaining salt from the round-bottom flask. This sequential application of filtration and distillation successfully separates sand, salt, and water.

Step-by-step solution

Understand the methods

Filtration is a technique used to separate solids from liquids by passing the mixture through a medium that allows the liquid to pass through but retains the solid particles. In this case, we can use filtration to remove sand from the mixture. Distillation is a process used to separate mixtures based on the differences in boiling points of their components. It involves heating the mixture until one component evaporates, and the vapor is then cooled to collect the separated component. We can use distillation to separate salt and water, as they have different boiling points.

Initial setup

Prepare a filtration setup with a funnel, filter paper, and a beaker. Also, prepare the distillation apparatus with a heat source, a round-bottom flask, a condenser, and a collecting flask.

Filtration of sand

Pour the mixture of sand, salt, and water through the filter paper placed in a funnel, with a beaker underneath to collect the filtrate (the liquid that passes through). The filter paper will stop the sand particles, leaving the saltwater in the beaker below. Carefully remove the sand from the filter paper and keep it aside. Now we have separated the sand from the mixture.

Distillation of saltwater

Pour the saltwater solution from the beaker into a round-bottom flask in the distillation apparatus. Start heating the flask slowly to increase the temperature of the saltwater. As water has a lower boiling point than salt, it will evaporate first, leaving the salt behind in the flask.

Collecting the components

As the water evaporates, the vapor will travel into the condenser, where it cools down and turns back into liquid. The condensed water will then collect in the collecting flask. Once all the water has been distilled, stop the heat source. We have now separated water from salt.

Collecting the salt

After the distillation process is complete, allow the round-bottom flask to cool down. The remaining salt can be collected from the inside of the flask. We have now successfully separated sand, salt, and water using sequential filtration and distillation methods.

Key concepts

Filtration

Understanding the concept of filtration is crucial when dealing with complex mixtures. Imagine a messy kitchen where you need to separate uncooked rice from water. You'd likely use a sieve that lets the water through but keeps the rice behind. That’s filtration at work. Similarly, in our exercise, filtration allows us to separate sand from a sand-salt-water mixture. Why does this work? Because the filter paper acts like a selective barrier, much like the sieve. It passes the smaller salt and water molecules through, while the larger sand particles get caught.

But why doesn't the filter paper capture the salt along with sand? It’s because salt dissolves in water, leaving no solid particles for the paper to catch. This simple yet effective separation method hinges on particle size and state of matter (solid or dissolved). It’s an elegant way to tidy up part of the messy mixture we started with, much like picking the larger bits of food waste from your sink water.

Distillation

Moving on to distillation, it's like a magic show where you bring a seemingly uniform liquid to a boil, and presto, you create two separate substances. But there’s no magic here, just science. In the scene from our exercise, we're left with saltwater after filtration. To pull apart this duo, we employ distillation, which relies on the fact that salt and water boil at different temperatures.

Picture a boiling pot on the stove, but instead of letting the steam just disappear into the air, we guide it through a cooling tube. The steam then transforms back into water—sans the salt. This process mirrors the Earth’s water cycle on miniaturized scale. The heat brings the water to its gaseous state, leaving the non-evaporating salt behind. Cooled, the water vapor returns to a liquid state, effectively separated. After this, you're left with a dry flask of salt and a separate container of distilled water. A little bit of heat, some cool physics, and voilà—separation complete!

Solids and Liquids Separation

Now let's tie it all together: separating solids from liquids often begins with understanding the properties of the materials we want to separate. In our mix, sand is a champion at being insoluble—it doesn’t dissolve in water. This characteristic makes it the perfect candidate for removal by filtration. Salt, on the other hand, dissolves well in water, but we exploit the boiling point magic to bid it farewell.

These methods of separation are not new tricks; they've been fundamental to processes from gold mining to cooking. Imagine trying to drain spaghetti without a colander—you'd likely lose a lot of your meal to the sink. Or consider making a cup of tea without getting rid of the tea leaves. By understanding the principles of filtration and distillation, you wield the power to separate, to purify, and arguably, to make the best cup of tea. The key takeaway is that these separation methods are not just academic—they're part of our lives, making them easier and a bit more mess-free.