Dilution | Definition, Equation & Factors

Which term describes a homogeneous mixture that isn't chemically combined?

• Solution

• Solute

• Solvent

• Suspension

Answer explanation

A solution is a homogeneous mixture where components are evenly distributed but not chemically combined. In contrast, solute and solvent refer to parts of a solution, while a suspension is a heterogeneous mixture.

What does molarity represent in a solution?

• Mass of solute per kilogram of solvent

• Number of moles of solute per liter of solution

• Volume of solvent per mole of solute

• Percentage of solute by mass

Answer explanation

Molarity is defined as the number of moles of solute per liter of solution. This measurement indicates the concentration of a solution, making the second answer choice the correct one.

Tags

NGSS.HS-PS1-5

Scientists often store chemicals as a concentrated stock solution primarily because it

• is safer to handle

• takes up less room

• has lower reactivity

• eliminates the need for dilution

Answer explanation

Scientists store chemicals as concentrated stock solutions primarily because it takes up less room. This allows for more efficient storage and easier handling in the laboratory.

When preparing a dilution, which piece of glassware must be used to achieve the desired volume and concentration?

• Beaker

• Graduated cylinder

• Volumetric flask

• Erlenmeyer flask

Answer explanation

A volumetric flask is specifically designed for precise dilutions, allowing accurate measurement of volume and concentration. Other glassware like beakers or graduated cylinders are less accurate for this purpose.

What is the correct safety practice when diluting strong acids like HCl?

• Add water to acid

• Add acid to water

• Mix acid and water simultaneously

• Heat the acid before dilution

Answer explanation

The correct practice is to add acid to water. This method minimizes the risk of exothermic reactions that can cause splattering, as adding water to acid can lead to violent reactions. Always prioritize safety when handling strong acids.

Which step is part of the proper procedure for diluting a stock solution using a volumetric flask?

• Fill the flask completely with solvent before adding stock

• Measure the stock solution after filling to the mark

• Add some solvent first, then add the measured stock, and finally fill to the mark

• Add the stock solution first, then adjust with solvent to any volume

Answer explanation

The correct procedure is to add some solvent first, then the measured stock solution, and finally fill to the mark. This ensures accurate dilution and prevents overflow or inaccurate measurements.

Observe the four graduated cylinders containing a solution. Which solution is the most dilute?

Organize these options into the right categories

Groups:

(a) Concentrated

,

(b) Dilute

• 
• Adding more water to an aqueous solution will make it more...

• A lot of solute compared to the amount of solvent.

• 
• A little solute compared to the amount of solvent.

• Adding more solute to a solution will make it more....

Tags

NGSS.MS-PS1-2

Arrange these solutions from diluted to concentrated:

• A, B, C, D

• B, A, D, C

• D, A, C, B

• B, C, A, D

Answer explanation

The correct order from diluted to concentrated is B, C, A, D. This arrangement reflects the increasing concentration levels of the solutions, with B being the most diluted and D the most concentrated.

What term refers to the process of reducing the concentration of a solute in a solution?

• Concentration

• Dilution

• Synthesis reaction

• Solution

Answer explanation

The term 'dilution' specifically refers to the process of reducing the concentration of a solute in a solution by adding more solvent. This distinguishes it from other terms like 'concentration' or 'solution', which do not describe this process.