Question

If a solution contains \(255 \mathrm{~mL}\) of ethanol and \(375 \mathrm{~mL}\) of water, what is the percent of ethanol in the solution?

Short answer

The percent of ethanol in the solution is approximately 40.48\%.

Step-by-step solution

- Identify Total Volume of the Solution

To find the percentage of ethanol in the solution, first, identify the total volume of the solution by adding the volume of ethanol and the volume of water together. Calculate as follows: \[ \text{Total Volume} = 255 \text{ mL (ethanol)} + 375 \text{ mL (water)} = 630 \text{ mL} \]

- Calculate the Percent of Ethanol

The percent of ethanol is found by dividing the volume of ethanol by the total volume of the solution, then multiplying by 100 to convert it to a percentage.Calculate using the formula:\[ \text{Percent of Ethanol} = \left( \frac{255}{630} \right) \times 100 \approx 40.48\% \]

Key concepts

Understanding Ethanol

Ethanol, often referred to as ethyl alcohol, is a colorless liquid commonly found in alcoholic beverages. It is also used industrially as a solvent and in biofuels. Ethanol has some unique physical and chemical properties. It is highly volatile, meaning it evaporates quickly when exposed to air. This property is significant when considering how mixtures or solutions involving ethanol behave.
Ethanol is miscible in water, meaning it can mix with water in any proportion without separating. This ability to mix without segregation simplifies calculations and analyses when ethanol is a component in a solution. Understanding ethanol's characteristics helps predict how it will interact within different solutions, essential for practical applications such as creating concentration solutions or understanding their behavior in chemical reactions.

Exploring Solution Composition

A solution is a homogeneous mixture where the solute is dissolved in the solvent. In our example, we consider a mixture of ethanol (solute) in water (solvent). What makes a solution's composition interesting is its uniform concentration throughout.
To describe a solution's composition, terms like "percent concentration" are used. Percent concentration specifically refers to the volume or mass of the solute compared to the entire solution's volume or mass, multiplied by 100 to get a percentage. In simpler terms, it tells us how much solute is present in every hundred parts of the total solution.
Recognizing the solution's homogeneous nature helps to understand how each component, be it ethanol or water, is distributed consistently within the solution. This is crucial for applications in chemistry and even culinary arts, where exact mixture ratios impact the final product's properties or taste.

Solution Volume Calculation

Calculating the total volume of a solution is a fundamental step in chemistry that helps determine other properties like concentration. In instances where you have a solution composed of two liquids, such as ethanol and water, you simply add both of their volumes together to get the overall solution volume.
For example, if you have 255 mL of ethanol and 375 mL of water, the total volume of the solution is 630 mL. This calculation assumes that the volumes are additive, which holds true in most real-world scenarios.
Once the total volume is known, it becomes easy to calculate the percent concentration or any other concentration metric you may need. This procedure underscores the importance of careful volume measurement and the additional calculations that follow to ascertain solution composition and properties.