If you mix 44 mL of 0.05 M K2HPO4 with 24 mL of 0.05 M KH2PO4, what % of the PO4 buffer is in the K2HPO4 form?
To determine the percentage of the PO4 buffer in the K2HPO4 form, we first need to calculate the moles of K2HPO4 and KH2PO4 in the given volumes.
The number of moles can be calculated using the formula:
moles = concentration * volume
Moles of K2HPO4:
0.05 M * 44 mL = 2.2 mmol
Moles of KH2PO4:
0.05 M * 24 mL = 1.2 mmol
To calculate the percentage of the PO4 buffer in the K2HPO4 form, we need to compare the moles of K2HPO4 to the total moles of phosphate buffer used.
Total moles of phosphate buffer = moles of K2HPO4 + moles of KH2PO4
Total moles of phosphate buffer = 2.2 mmol + 1.2 mmol = 3.4 mmol
Percentage of PO4 buffer in K2HPO4 form = (moles of K2HPO4 / total moles of phosphate buffer) * 100%
Percentage of PO4 buffer in K2HPO4 form = (2.2 mmol / 3.4 mmol) * 100%
Percentage of PO4 buffer in K2HPO4 form = 64.71%
Therefore, approximately 64.71% of the PO4 buffer is in the K2HPO4 form.
To find the percentage of the PO4 buffer in the K2HPO4 form, we need to calculate the concentrations of K2HPO4 and KH2PO4 after mixing the solutions.
Let's start by calculating the moles of K2HPO4 and KH2PO4 in the solutions.
Molarity (M) = moles/volume (L)
For K2HPO4:
Molarity (K2HPO4) = 0.05 M
Volume (K2HPO4) = 44 mL = 0.044 L
Moles (K2HPO4) = Molarity x Volume
= 0.05 M x 0.044 L
= 0.0022 moles
For KH2PO4:
Molarity (KH2PO4) = 0.05 M
Volume (KH2PO4) = 24 mL = 0.024 L
Moles (KH2PO4) = Molarity x Volume
= 0.05 M x 0.024 L
= 0.0012 moles
Now, we can determine the ratio of K2HPO4 to total phosphate (PO4) buffer.
Total phosphate buffer (PO4) = moles (K2HPO4) + moles (KH2PO4)
= 0.0022 moles + 0.0012 moles
= 0.0034 moles
Percentage of PO4 buffer in K2HPO4 form = (moles (K2HPO4) / total phosphate buffer) x 100
= (0.0022 moles / 0.0034 moles) x 100
≈ 64.71%
Therefore, approximately 64.71% of the PO4 buffer is in the K2HPO4 form.