## dilutions? [ENDORSED]

mcredi
Posts: 63
Joined: Fri Sep 28, 2018 12:16 am

### dilutions?

Could someone please explain to me the general steps for how to complete a dilution problem?

Hanlin Zhu 4G
Posts: 30
Joined: Fri Sep 28, 2018 12:28 am

### Re: dilutions?  [ENDORSED]

The exact steps may vary depends on the types of values are given. The key concept is that when diluting a solution, the moles of solute remain the same. The moles of solute = M initial × V initial = M final × V final. So it might be helpful to first think about which of those quantities were given, try to plug in some numbers, and then solve for the unknown one.

paytonm1H
Posts: 74
Joined: Fri Sep 28, 2018 12:18 am

### Re: dilutions?

m1v1=m2v2 will be your best friend! Also, here is Lavelle's video module on molarity and dilution of a solution!
https://lavelle.chem.ucla.edu/wp-conten ... n.wmv.html

Carine Tamamian 2B
Posts: 61
Joined: Fri Sep 28, 2018 12:23 am

### Re: dilutions?

M1V1=M2V2 is the main equation for dilutions! M=n(mol)/v(l) and you can move the equation around depending on your given in the problem. Also make sure all the units are the same in your equation.

Posts: 47
Joined: Fri Sep 28, 2018 12:15 am

### Re: dilutions?

I solved most dilution problems by using the equation Molarity(M)= mol of solute (n) / vol of solution (V). From this equation, we know that when diluting the solution, the moles of solute remain the same. So, n(initial)=n(final), and also M(initial)V(initial)=M(final)V(final). Using this formula, problems usually give 3 of these 4 values needed, so I can manipulate the formula to find the missing value.

Nicolette_Canlian_2L
Posts: 77
Joined: Fri Sep 28, 2018 12:25 am
Been upvoted: 1 time

### Re: dilutions?

Sometimes the problem won't directly give you the initial molarity, so you might have to convert the given mass of solute to moles. Then divide by the volume of the solvent to find the initial molarity.