Question

Calculate the mass percent of sodium acetate in each of the following solutions. a. \(5.00 \mathrm{g}\) of sodium acetate in \(25.0 \mathrm{g}\) of water b. \(10.0 \mathrm{g}\) of sodium acetate in \(25.0 \mathrm{g}\) of water c. \(15.0 \mathrm{g}\) of sodium acetate in \(25.0 \mathrm{g}\) of water d. \(20.0 \mathrm{g}\) of sodium acetate in \(25.0 \mathrm{g}\) of water

Short answer

The mass percent of sodium acetate in each solution is: a. \(16.67 \%\) b. \(28.57 \%\) c. \(37.50 \%\) d. \(44.44 \%\).

Step-by-step solution

Calculate the total mass of the solution

Add the mass of sodium acetate and the mass of water in each case to find the total mass of the solution. a. Total mass = \(5.0 \ \text{g}\) (sodium acetate) + \(25.0 \ \text{g}\) (water) = \(30.0 \ \text{g}\) b. Total mass = \(10.0 \ \text{g}\) (sodium acetate) + \(25.0 \ \text{g}\) (water) = \(35.0 \ \text{g}\) c. Total mass = \(15.0 \ \text{g}\) (sodium acetate) + \(25.0 \ \text{g}\) (water) = \(40.0 \ \text{g}\) d. Total mass = \(20.0 \ \text{g}\) (sodium acetate) + \(25.0 \ \text{g}\) (water) = \(45.0 \ \text{g}\)

Calculate the mass percent of sodium acetate in each case

Divide the mass of sodium acetate by the total mass of the solution and then multiply by 100 to find the mass percent. a. Mass percent = \(\frac{5.0 \ \text{g}}{30.0 \ \text{g}} \times 100 = 16.67 \%\) b. Mass percent = \(\frac{10.0 \ \text{g}}{35.0 \ \text{g}} \times 100 = 28.57 \%\) c. Mass percent = \(\frac{15.0 \ \text{g}}{40.0 \ \text{g}} \times 100 = 37.50 \%\) d. Mass percent = \(\frac{20.0 \ \text{g}}{45.0 \ \text{g}} \times 100 = 44.44 \%\) So the mass percent of sodium acetate in each solution are: a. \(16.67 \%\) b. \(28.57 \%\) c. \(37.50 \%\) d. \(44.44 \%\) Keep in mind that the mass percent is a way to express the concentration of a solute in a solution, and can be helpful in comparing the relative amounts of solute and solvent.

Key concepts

Sodium Acetate

Sodium acetate is a salt that is formed by the reaction of acetic acid with sodium bicarbonate or sodium hydroxide. This white powder is commonly used in various industrial applications as well as in laboratories. It acts as a buffer in biochemistry, helping to maintain a stable pH in solutions, which is crucial for many chemical reactions and processes.

In everyday life, sodium acetate can be found in heating pads and hot ice demonstrations, where it rapidly crystallizes, releasing heat. Understanding the concentration of sodium acetate in a solution, like in the given exercise, is essential for ensuring its effectiveness and safety during use. Sodium acetate solutions are also used in culinary settings, sometimes appearing as a seasoning on foods.

• A hygroscopic substance, meaning it absorbs moisture from the air
• Often used as a de-icing agent
• Slight vinegar odor due to its acetic acid parent

Solution Concentration

Solution concentration is a measurement of how much solute is present in a given quantity of solvent or solution. It's an important concept in chemistry because it helps determine the potency and reactivity of a solution. The mass percent technique, used in the resolution of the current exercise, is one method to express solution concentration.

Mass percent is calculated by dividing the mass of the solute by the total mass of the solution and multiplying the result by 100, which gives the percentage of the solute in the entire mixture. It's particularly useful for comparing different solutions because it provides a straightforward way to understand how much of a substance is dissolved in a liquid.

• Expressed in percentage, making it easy to interpret
• Helps in chemical recipes to get desired reactant concentrations
• Allows scientists to scale up reactions from the laboratory to industrial scales

Chemistry Calculation

In chemistry, calculations like finding the mass percent are fundamental skills that help chemists understand the properties of their solutions. Each calculation relies on clear, logical steps that ensure accuracy and repeatability.

The exercise given requires adding the amounts of sodium acetate and water first to determine the complete mass of each solution. Then, dividing the mass of the sodium acetate by this total mass provides how much of the total solution is actually sodium acetate.

• Understanding the mathematical formula: \( \text{Mass percent} = \left(\frac{\text{mass of solute}}{\text{total mass of solution}} \right) \times 100 \)
• Precision in measuring masses
• Ensuring no constraints such as temperature shifts or impurities that could affect results

Solute and Solvent

In any solution, there are two primary components: the solute and the solvent. The solute is the substance that gets dissolved, while the solvent is the material that does the dissolving. In the context of the given exercise, sodium acetate is the solute, and water is the solvent.

Identifying these components is key to conducting chemistry calculations and understanding how solutions behave. The interactions between solute and solvent can affect factors like conductivity, boiling and freezing points, and overall solution stability.

• Solute: smaller component, determines concentration and chemical behavior
• Solvent: larger component, usually dictates the state of the solution (liquid)
• Effective understanding ensures proper experimental setups and chemical reactions