Not for homework, just practice problems I'm having trouble with.

Knowing that one mole of KHP, C8H5O4K, reacts with one mole of NaOH, what mass of KHP is required to neutralize 30.0 mL of the 0.10 M NaOH solution?

if 24.5 mL of the 0.10 M NaOH solution is required to reach the endpoint in a titration with an unknown monoprotic acid, how many moles of the acid were present?

Okay, I think i understand the second question.

moles=MxV
so...
moles=(24.5ml)(0.10M NaOH) = 2.45 moles
??

To solve these problems, we'll use the concept of stoichiometry and the equation of the reaction between KHP and NaOH.

In the first problem, we're given the volume and the concentration of the NaOH solution. We need to find the mass of KHP required to neutralize this solution.

Step 1: Write the balanced equation for the reaction between KHP and NaOH:
KHP + NaOH -> H2O + NaKP

Step 2: Find the moles of NaOH:
Using the formula c = n/V (concentration = moles/volume), we can rearrange the formula to solve for moles: n = c * V.
n = 0.10 mol/L * 30.0 mL * (1 L/1000 mL) = 0.003 moles of NaOH.

Step 3: Use the stoichiometry from the balanced equation to find the moles of KHP:
From the balanced equation, we see that 1 mole of KHP reacts with 1 mole of NaOH. Therefore, the number of moles of KHP is also 0.003 moles.

Step 4: Convert moles of KHP to the mass of KHP:
The molar mass of KHP (C8H5O4K) can be calculated using the atomic masses from the periodic table:
Molar mass of K: 39.10 g/mol
Molar mass of H: 1.01 g/mol
Molar mass of C: 12.01 g/mol
Molar mass of O: 16.00 g/mol

Add them up:
39.10 g/mol + (5 * 1.01 g/mol) + (8 * 12.01 g/mol) + (4 * 16.00 g/mol) = 204.23 g/mol

Now, multiply the moles of KHP by the molar mass to get the mass:
Mass of KHP = 0.003 moles * 204.23 g/mol = 0.6127 grams.

Therefore, 0.6127 grams of KHP is required to neutralize 30.0 mL of the 0.10 M NaOH solution.

Now, let's move on to the second problem.

This time, we're given the volume and concentration of NaOH used to neutralize an unknown monoprotic acid. We need to find the number of moles of the acid present.

Step 1: Write the balanced equation for the reaction between the unknown acid and NaOH:
Unknown acid + NaOH -> H2O + Sodium salt of acid

Step 2: Find the moles of NaOH:
Using the formula c = n/V, we can rearrange the formula to solve for moles: n = c * V.
n = 0.10 mol/L * 24.5 mL * (1 L/1000 mL) = 0.00245 moles of NaOH.

Step 3: Use the stoichiometry from the balanced equation to find the moles of the unknown acid:
From the balanced equation, we see that 1 mole of NaOH reacts with 1 mole of the unknown acid. Therefore, the number of moles of the unknown acid is also 0.00245 moles.

Therefore, 0.00245 moles of the unknown monoprotic acid were present.