1) Calculate the molarity of a solution of sodium hydroxide, NaOH,if 23.64 mL of this solution is needed to neutralize 0.5632g of potassium hydrogen phthalate.

2) It is found that 24.68 mL of 0.1165M NaOH is needed to titrate 0.2931 g of an unknown acid to the phenolphthalein end point. Calculate the equivalent mass of the acid.

I have the same thing. I dnt know the second one but the first I ended up getting. .1167mmoles/ml

hey guisee im a chem teeecher and i say ur probably right on that, as long as you take the variable Y into account, and then use the 5 percent rule. that will make hydrogen bonding possible, and return a value of .1167. :)

1) Molarity is the number of moles of solute per liter of solution. To calculate the molarity, we need to find the number of moles of sodium hydroxide.

First, calculate the number of moles of potassium hydrogen phthalate:
Molar mass of potassium hydrogen phthalate (KHP): 204.23 g/mol
Number of moles of KHP = mass / molar mass = 0.5632 g / 204.23 g/mol

Now, we need to find the molarity of sodium hydroxide:
Volume of NaOH solution used = 23.64 mL = 0.02364 L

Molarity (M) = moles of solute / volume of solution in liters
Molarity = (0.5632 g / 204.23 g/mol) / 0.02364 L

Calculating all that... (wait for it)... gives us the molarity of sodium hydroxide solution.

2) To calculate the equivalent mass of the acid, we need to use the equation:
Molarity (M) = moles of solute / volume of solution in liters

First, convert the mass of the unknown acid to moles:
Molar mass of unknown acid = ?
Moles of unknown acid = mass / molar mass

Now, we can find the moles of NaOH used:
Molar mass of NaOH = 39.997 g/mol
Moles of NaOH = molarity x volume in liters = 0.1165 mol/L x 0.02468 L

Finally, to find the equivalent mass of the acid, divide the mass of the unknown acid by the number of moles:
Equivalent mass = mass of the unknown acid / moles of unknown acid

And voila! You've got the equivalent mass of the acid.

To calculate the molarity of a solution, you need to know the number of moles of solute and the volume of the solution in liters. Here's how you can calculate the molarity in each case:

1) To calculate the molarity of sodium hydroxide (NaOH), you need to determine the number of moles of NaOH and the volume of the solution in liters.

First, find the number of moles of NaOH using the molar mass of NaOH, which is 22.99 g/mol for Na, 15.999 g/mol for O, and 1.007 g/mol for H.

Moles of NaOH = Mass of NaOH / Molar mass of NaOH
= 0.5632 g / (22.99 g/mol + 15.999 g/mol + 1.007 g/mol)
= 0.02384 mol

Next, convert the volume of the solution from milliliters (mL) to liters (L). In this case, the volume is given as 23.64 mL.

Volume of solution (L) = 23.64 mL / 1000 mL/L
= 0.02364 L

Finally, calculate the molarity (M) using the formula:

Molarity (M) = Moles of NaOH / Volume of solution (L)
= 0.02384 mol / 0.02364 L
= 1.01 M

Therefore, the molarity of the sodium hydroxide solution is 1.01 M.

2) To calculate the equivalent mass of the unknown acid, first, determine the number of moles of NaOH and the volume of the solution in liters.

Using the given molarity of NaOH (0.1165 M) and the volume of NaOH solution (24.68 mL), calculate the number of moles of NaOH:

Moles of NaOH = Molarity × Volume of NaOH solution (L)
= 0.1165 mol/L × (24.68 mL / 1000 mL/L)
= 0.002875 mol

Next, determine the number of moles of the unknown acid by using the stoichiometric ratio between NaOH and the unknown acid. From the balanced chemical equation, 1 mole of NaOH reacts with 1 mole of the unknown acid.

Moles of unknown acid = Moles of NaOH
= 0.002875 mol

Now, calculate the mass of the unknown acid using the given molar mass of the unknown acid, which is not provided in the question. You will need this value to proceed further.

Finally, divide the calculated mass of the unknown acid (in grams) by the number of moles of the unknown acid (in moles) to determine the equivalent mass:

Equivalent mass of acid = Mass of unknown acid (g) / Moles of unknown acid (mol)

Since the molar mass of the unknown acid is not given, you cannot accurately calculate the equivalent mass of the acid without this information.

IS IT 0.1167 M ?????

0.1167 is right.

#2.
Use mL x N x milliequivalent weight = grams.
You have mL, M(same as normality in this case), and grams. Solve for milliequivalent weight, then multiply by 1000.
Be patient. All of us are volunteers and we get around as fast as we can.