calculate the molarity of k+ in a soln prepared by adding .2L of .200M K3PO4 and 75.0mL of .5M K3PO4. assume volumes are additive.
A few of steps here and more than one way to answer the problem
You need to calculate the total number of moles of K3PO4 from the two volumes and two concentrations.
This is in the total volume of 0.2 L+0.075 L=
You can now calculate the molarity of K3PO4 in moles/L
Assume that the K3PO4 dissociates to
3K^+ and PO4^3-
you can now calculate the [K+]
Tip - try not to forget the leading zeros as I nearly read 2 L rather than 0.2 L 8-))
To calculate the molarity of K+ in the solution, you'll need to follow a few steps.
Step 1: Calculate the total volume of the solution.
The total volume of the solution is the sum of the volumes of the two components. In this case, it is 0.2 L (from the first component) + 0.075 L (from the second component) = 0.275 L.
Step 2: Calculate the total number of moles of K3PO4.
To do this, you'll need to use the formula:
moles = concentration × volume.
For the first component: moles = 0.200 M × 0.2 L = 0.04 moles of K3PO4.
For the second component: moles = 0.500 M × 0.075 L = 0.0375 moles of K3PO4.
So, the total number of moles of K3PO4 in the solution is 0.04 moles + 0.0375 moles = 0.0775 moles.
Step 3: Calculate the molarity of K+.
Since the K3PO4 dissociates into 3 K+ ions, the number of moles of K+ will be three times the number of moles of K3PO4.
moles of K+ = 3 × 0.0775 moles = 0.2325 moles.
Finally, divide the moles of K+ by the total volume of the solution to get the molarity (M) of K+.
molarity of K+ = moles of K+ / total volume
molarity of K+ = 0.2325 moles / 0.275 L = 0.845 M (rounded to three decimal places).
So, the molarity of K+ in the solution is 0.845 M.