Which equation expresses dilutions?

Which equation expresses dilutions?

• A. M1V1 = M2V2
• B. M1/M2 = V2/V1
• C. V1 = V2
• D. M1 = M2

Answer: (A)

Dilution keeps the amount of solute the same while increasing the solvent volume, so the number of moles stays constant. That yields M1V1 = M2V2, because concentration times volume gives moles, and the moles before dilution (M1V1) equal the moles after dilution (M2V2). This form directly links the initial and final states and is the clearest way to solve for any unknown. You can rearrange the same relation to M1/M2 = V2/V1, but the straightforward product form is most commonly used because it reflects the conservation of moles without extra steps. The other options don’t fit dilution: V1 = V2 implies no change in volume, which means no dilution, and M1 = M2 implies no change in concentration, which also contradicts the dilution process.

Dilution keeps the amount of solute the same while increasing the solvent volume, so the number of moles stays constant. That yields M1V1 = M2V2, because concentration times volume gives moles, and the moles before dilution (M1V1) equal the moles after dilution (M2V2). This form directly links the initial and final states and is the clearest way to solve for any unknown.

You can rearrange the same relation to M1/M2 = V2/V1, but the straightforward product form is most commonly used because it reflects the conservation of moles without extra steps. The other options don’t fit dilution: V1 = V2 implies no change in volume, which means no dilution, and M1 = M2 implies no change in concentration, which also contradicts the dilution process.