Question

Flour is mixed with powdered sugar, and then the combination is ground to a fine dust. Is the resulting product a solution or a heterogeneous mixture? Explain.

Short answer

The resulting product of mixed and ground flour and powdered sugar is a heterogeneous mixture because the particles of flour and sugar are not dissolved in each other but rather mixed together, and the components can still be separated as they are not chemically combined or uniformly distributed at the molecular level.

Step-by-step solution

Define a solution

A solution is a homogeneous mixture of two or more substances, where one substance, called the solute, dissolves uniformly into the other substance, called the solvent. In solutions, the particles of the solute are evenly distributed throughout the mixture and cannot be easily separated. Examples of solutions include saltwater and sugar dissolved in water.

Define a heterogeneous mixture

A heterogeneous mixture is a mixture of two or more substances that do not blend uniformly, resulting in distinguishable components or regions within the mixture. The substances are not dissolved in each other and can often be separated easily. Examples of heterogeneous mixtures include sand and water, muesli cereal, and oil and vinegar salad dressing.

Analyze flour and powdered sugar

Flour and powdered sugar are both solid substances. When they are combined and ground into a fine dust, the two substances are mixed into a single mixture. However, the flour and sugar particles do not dissolve into each other. Considering these definitions and properties of the substances involved, we can now categorize the resulting product. Solution:

Identify the product as a solution or a heterogeneous mixture

The resulting product of mixed and ground flour and powdered sugar is a heterogeneous mixture. This is because the particles of flour and sugar are not dissolved in each other but rather mixed together. The components of the mixture can still be separated, as they are not chemically combined or uniformly distributed at the molecular level.

Key concepts

Solution

In chemistry, a solution is a type of homogeneous mixture where one substance, known as the solute, is dissolved uniformly into another substance, called the solvent. For example, when you mix sugar and water, the sugar dissolves completely, creating a solution.

Solutions are special because the solute particles are evenly distributed throughout the mixture. This means that if you take two samples from a solution, they will contain the same amount of solute. Another interesting aspect of solutions is that the solute cannot be easily separated from the solvent using simple physical methods like filtering. Instead, you would need to evaporate the solvent or use other chemical processes.

• The mixing at the molecular level is a key characteristic differentiating solutions from other types of mixtures.
• Solutions can be found in various forms such as gases, liquids, or solids.
• Common examples include sugar in water, salt in water, and even air, which is a solution of different gases.

Homogeneous Mixture

A homogeneous mixture is a mixture where the components are evenly distributed, giving the mixture a uniform appearance. Unlike heterogeneous mixtures, there are no visible boundaries or parts within a homogeneous mixture.

This uniformity means when you look at a homogeneous mixture, it appears as a single phase. An example is saltwater, where the salt is evenly spread throughout the water, forming a single clear liquid. Homogeneous mixtures are often called solutions when they involve a solvent and a solute.

• They are not only limited to liquid solutions but can also include gas mixtures like air and solid solutions like alloys (e.g., brass).
• The key idea is that all parts of the mixture are the same as any other part.
• One cannot easily identify or separate the individual components by simple inspection.

Solute

The solute in a solution is the substance that is dissolved in the solvent. It is usually present in a lesser amount than the solvent and is what gives solutions their specific characteristics or flavors. For example, in a sugar-water solution, sugar is the solute, and it gives the water its sweetness.

Solutes can be in any physical state: solid, liquid, or gas. The process of dissolving solute into a solvent involves breaking solute particles down and dispersing them uniformly throughout the solvent. This can sometimes require stirring or heating to help the solute dissolve more completely.

• The solute can affect the collective properties of the solution, such as its boiling point, freezing point, and even its electrical conductivity.
• An important factor for how well a solute dissolves is the nature of both the solute and the solvent, which is often described by the phrase "like dissolves like."
• Polar solutes tend to dissolve well in polar solvents, and nonpolar solutes dissolve well in nonpolar solvents.