calculate the final concentration if 4.0 L of 1.5 M NaCl and 2.0 L of 3.0M NaCl are mixed.
I am confused about how to calculate the final concentration. We are currently working on solutions. I think first I need to divide the amount of the solution by the amount of the solute and then do the mass percent or do I use moles of a solute divided by L of solution?
Would it be volume divided by moles then convert to g
mols is the only way to go.
4.0 L x 1.5 M = ?? mols NaCl
2.0 L x 3.0 M = ?? mols NaCl.
Total mols NaCl/total L NaCl = M NaCl.
To calculate the final concentration of a solution after mixing, you need to use the formula:
C1V1 + C2V2 = CfinalVfinal
where C1 and C2 are the initial concentrations of the two solutions, V1 and V2 are their respective volumes, and Cfinal and Vfinal are the final concentration and volume of the mixed solution.
In this case, you have two solutions of NaCl, one with a concentration of 1.5 M and a volume of 4.0 L, and the other with a concentration of 3.0 M and a volume of 2.0 L. To find the final concentration, you can substitute the given values into the formula:
(1.5 M)(4.0 L) + (3.0 M)(2.0 L) = CfinalVfinal
Simplifying this equation, you get:
6.0 + 6.0 = CfinalVfinal
12.0 = CfinalVfinal
Since we're interested in the final concentration, we can solve for Cfinal by dividing both sides of the equation by Vfinal:
Cfinal = 12.0 / Vfinal
Now, if you want to calculate the final concentration in terms of moles per liter (M), you can divide the concentration in moles (Cfinal = 12.0) by the final volume of the solution after mixing (Vfinal).
For example, if the final volume is 6.0 liters, you would divide 12.0 moles by 6.0 liters to find the final concentration:
Cfinal = 12.0 moles / 6.0 liters
Cfinal = 2.0 M
Therefore, the final concentration of the mixed solution would be 2.0 M if the final volume is 6.0 liters.
Remember to always pay attention to units and use proper conversions (if necessary) to ensure accurate calculations.