Concentration vs Dilution?

[Gabby Sigal 3H]

Can someone clarify when we're supposed to use the equation Minitial*Vinitial=Mfinal*Vfinal vs V=n(moles)/c (molarity) when trying to find the volume needed for a specific solution?

[Hannah Choi 1K]

The M_initialV_initial = M_finalV_final equation is usually used to find volume when we are:
a) trying to find the volume of a dilution (V_final) with molarity M_final after a solution with volume V_initial and concentration M_initial is diluted
b) trying to find the original volume of a solution (V_initial) with molarity M_initial from a dilution with volume V_final and molarity M_final

The V =n/c equation is derived from the definition of molarity, where molarity = moles per liter (c = n/L) equation.
If used to find volume, it is probably used for simpler volume calculations, like trying to find the volume of a solution with molarity x mol/L and y moles of solute.

[Rose Arcallana 2B]

If you're just trying to find the volume of a solution, it is easier to use M (molarity) = n (moles)/ V (volume). But once they specified a change in molarity which they want you to find the volume to reach that specific molarity you use the MinitialVinitial = MfinalVfinal. :)

[Mihir Sukhatme 1D]

To use M1(v1) = M2(v2), you have to be given enough information to figure out at least three of the components. But it could be given in terms of moles and has to be converted to Molarity or something along those lines.

[daniellediem1k]

It depends on what information is given in the problem. MV = MV is often used when finding the new molarity of a solute when it is placed in a new solution with a different volume.

[Aaron Tang 2F]

Minitial*Vinitial=Mfinal*Vfinal is used when you are given the volume or molarity of a solution, that is then diluted. You may be given the volume of this new solution, where you will use the formula to find the molarity or vice versa. Or you may be given the volume and molarity of the diluted solution and asked to solve for the original. V=n(moles)/c (molarity) is used when any one of the values is missing for only one solution.

[oliviahelou]

To find the volume or concentration while doing a dilution use the M1V1=M2V2 EQUATION. However, when you're looking for a volume in general, just use the other formula, as u don't have an initial and final volume and molarity.

[Milli Zunich 3I]

It's for volume but make sure you have the components for the equation. There's also another equation you can use, but that takes different parameters.

[isabella garcia - 1G]

You would use MinitialVinitial = MfinalVfinal when given certain components to a question that concerns calculating the molarity of volume of something that was diluted.

[Sofi Ghasemzadeh 2G]

Use the simplest equation that can be used with the amount of information given.

[Claudia Longo 2J]

Can someone clarify when we're supposed to use the equation Minitial*Vinitial=Mfinal*Vfinal vs V=n(moles)/c (molarity) when trying to find the volume needed for a specific solution?

A big hint will be the given values in the problem, which goes back to the problem solving skill Dr. Lavelle emphasized in the beginning of the class. For example, it is a lot more likely that you will use Minitial*Vinitial=Mfinal*Vfinal if you are given Minitial, Mfinal, and Vfinal and you will solve for Vinitial. Example values could be 0.25 M, 0.34 M and 25 mL. These equations may have to be used in conjunction with one another.

[Marilyn]

It'll depend on the information given to you in the problem.

[AndreyCastellanos 3H]

1) use M (molarity) = n (moles)/ V (volume)
2) Minitial-Vintial = Mfinal-Vfinal

[205282258]

if there is a change in the molarity of a solution and you are given a final or initial molarity then you will most likely be using the M1V1 = M2V2 equation.