Molarity of NaOH solution = 0.06115
Volume of NaOH used = 15.50 mL
Volume of unknown Sample = 10.00 mL
Find the Moles of NaOH used?
Find the molarity of H3PO4?
Thanks!
To which end point did you titrate; i.e. how many of the H^+ were neutralized. If all three then
H3PO4 + 3NaOH ==> Na3PO4 + 3H2O
mols NaOH = M x L = ?
mols H3PO4 = 1/3 that.
M H3PO4 = mols H3PO4/L H3PO4
Frankly, I doubt you neutralized all three; you will need to adjust the above if less than three.
To find the moles of NaOH used, we can use the formula:
Moles = Molarity * Volume
Given:
Molarity of NaOH solution = 0.06115 M
Volume of NaOH used = 15.50 mL
Converting the volume from milliliters to liters:
Volume of NaOH used = 15.50 mL / 1000 mL/L = 0.01550 L
Now we can calculate the moles of NaOH used:
Moles of NaOH used = 0.06115 M * 0.01550 L = 0.000947 moles
Therefore, the moles of NaOH used is 0.000947 moles.
To find the molarity of H3PO4, we need to use the balanced chemical equation and the moles of reactants and products:
2 NaOH + H3PO4 -> Na2HPO4 + 2 H2O
From the balanced equation, we can see that 2 moles of NaOH react with 1 mole of H3PO4. Therefore, the ratio of moles of NaOH to moles of H3PO4 is 2:1.
Given:
Moles of NaOH used = 0.000947 moles
Since the ratio of NaOH to H3PO4 is 2:1, the moles of H3PO4 will be half of the moles of NaOH used:
Moles of H3PO4 = 0.000947 moles / 2 = 0.000474 moles
Now that we know the moles of H3PO4, we can calculate the molarity using the formula:
Molarity = Moles / Volume
Given:
Volume of unknown sample = 10.00 mL
Converting the volume from milliliters to liters:
Volume of unknown sample = 10.00 mL / 1000 mL/L = 0.01000 L
Now we can calculate the molarity of H3PO4:
Molarity of H3PO4 = 0.000474 moles / 0.01000 L = 0.0474 M
Therefore, the molarity of H3PO4 is 0.0474 M.