How does dilution affect molarity?
Diluting a sample will reduce the molarity.
For example if you have 5mL of a 2M solution which is diluted to a new volume of 10mL the molarity will be reduced to 1M.
To solve a problem like this one you'll apply the equation:
This would be solved to find
Here is a video that describes this process and provides another example of how to calculate the change in molarity when a solution is diluted.