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### Which Volume to use for M1

Posted: Sat Oct 05, 2019 6:03 pm
Some questions give you a volume and then take out a smaller volume to produce another solution. When using the equation M1V1=M2V2, which of the two volumes do we use for M1.

### Re: Which Volume to use for M1

Posted: Sat Oct 05, 2019 6:13 pm
The first volume given usually allows you to calculate the molarity. Typically we use the second volume in the calculation.

### Re: Which Volume to use for M1

Posted: Sat Oct 05, 2019 7:02 pm
Another way to think about what is MI VI and what is M2 V2, you can think of the first set of variables as your stock solution (before dilution) and your second set of variables are a part of your desired solution (after dilution).

### Re: Which Volume to use for M1

Posted: Sun Oct 06, 2019 12:38 am
it depends on what the question is asking for. Usually you would use the smaller one

### Re: Which Volume to use for M1

Posted: Sun Oct 06, 2019 12:51 am
V1 is usually the initial volume that you use to create the second molarity, so if you are solving for V2, you use the smaller volume in the equation for M1.

### Re: Which Volume to use for M1

Posted: Sun Oct 06, 2019 2:14 pm
M1 should always be your starting point and M2 is what is produced through the reaction, so when the equation says this is ‘produced’ it is referring to M2.

### Re: Which Volume to use for M1

Posted: Sun Oct 06, 2019 4:09 pm
I always write M1V1 as MiVi to help me remember that those are the initial volumes and molarity for the problems.