What is the pH of the resulting solution when 25.0mL of 0.100 HNO3(aq)are reacted with 20.0 mL of 0.175M NaOH(aq)? Is the resulting solution acidic or basic in nature?
HNO3 + NaOH ==> NaNO3 + H2O
mols HNO3 = M x L = approx 0.0025
mols NaOH = M x L = approx 0.0035
excess NaOH available is approx 0.001mols
M NaOH = mols/L = 0.001/0.045 = approx 0.02M
You need to redo all of these calculations since I've estimated.
Then poH = -log(OH^-)
Calculate pOH and substitute into the equation below.
pH + pOH = pKw = 14
You know pKw and pOH, solve for pH.
Is the solution acidic or basic?
pH<7 = acidic
pH=7 - neutral
pH>7 = basic
That was super helpful, thanks!
To find the pH of the resulting solution, we need to determine the moles of acid (HNO3) and base (NaOH) that react, as well as the concentration of the resulting solution.
Step 1: Calculate the moles of HNO3:
moles of HNO3 = volume (L) x concentration (M)
= 25.0 mL x 0.100 M
= 0.0025 moles of HNO3
Step 2: Calculate the moles of NaOH:
moles of NaOH = volume (L) x concentration (M)
= 20.0 mL x 0.175 M
= 0.0035 moles of NaOH
Step 3: Determine the limiting reactant:
The limiting reactant is the one that is completely consumed in the reaction. Compare the moles of HNO3 and NaOH calculated above. HNO3 is the limiting reactant because it has fewer moles.
Step 4: Determine the excess reactant:
The excess reactant is the one that is not completely consumed. In this case, NaOH is the excess reactant.
Step 5: Calculate the moles of the excess reactant remaining:
To find the moles of NaOH remaining, subtract the moles of NaOH reacted (0.0025 moles) from the total moles (0.0035 moles):
moles of NaOH remaining = 0.0035 - 0.0025
= 0.001 moles of NaOH remaining
Step 6: Calculate the moles of water formed:
Since the balanced chemical equation for the reaction is 1:1, the same number of moles of water is formed as the limiting reactant (0.0025 moles).
Step 7: Calculate the total volume of the resulting solution:
To find the total volume of the resulting solution, add the volumes of the acid and base:
total volume = volume of acid + volume of base
= 25.0 mL + 20.0 mL
= 45.0 mL
= 0.045 L
Step 8: Calculate the concentration of the resulting solution:
To find the concentration, divide the moles of HNO3 by the total volume:
concentration = moles/volume
= 0.0025 moles/0.045 L
= 0.0556 M
Step 9: Calculate the pH of the resulting solution:
The pH of a solution is determined by the concentration of H+ ions. Since HNO3 is a strong acid, it dissociates completely in water. This means that the concentration of H+ ions is the same as the concentration of HNO3.
pH = -log[H+]
= -log(0.0556)
≈ -(-1.255)
≈ 1.255
So, the pH of the resulting solution is approximately 1.255.
Step 10: Determine the nature of the resulting solution:
Since the pH is less than 7, the resulting solution is acidic in nature.