Question

The concentration of a certain sodium hydroxide solution was determined by using the solution to titrate a sample of potassium hydrogen phthalate (abbreviated as KHP). KHP is an acid with one acidic hydrogen and a molar mass of 204.22 g/mol. In the titration, 24.46 mL of the sodium hydroxide solution was required to react with 0.1082 g KHP. Calculate the molarity of the sodium hydroxide.

Answer 1

To find the molarity of the NaOH solution used in titrating KHP, one must calculate the moles of KHP based on its mass and molar mass, then determine the equal number of moles of NaOH reacting, and divide these moles by the volume of NaOH solution in liters, resulting in a molarity of 0.0217 M.

Step-by-step explanation:

To calculate the molarity of the sodium hydroxide (NaOH) solution used in titration, the first step is to find the number of moles of potassium hydrogen phthalate (KHP) reacted. Given that KHP has a molar mass of 204.22 g/mol, the moles of KHP is calculated by dividing the mass of KHP by its molar mass:

Moles of KHP = 0.1082 g / 204.22 g/mol = 0.00053 mol

The balanced chemical equation for the reaction between KHP and NaOH is as follows:

KHP (aq) + NaOH (aq) → KNaP (aq) + H₂O (l)

Since the stoichiometry of the reaction is 1:1, the moles of NaOH are equal to the moles of KHP. Thus, the moles of NaOH is also 0.00053 mol. Finally, the molarity (M) of NaOH is the moles of NaOH divided by the volume of NaOH solution in liters:

Molarity of NaOH = Moles NaOH / Volume NaOH (L)

Molarity of NaOH = 0.00053 mol / 0.02446 L = 0.0217 M

Therefore, the molarity of the NaOH solution is 0.0217 M.

Answer 2

`Molarity_(NaOH)=0.02166\ M`

Step-by-step explanation:

Moles of KHP :

Given, Mass of KHP = 0.1082 g

Molar mass of KHP = 204.22 g/mol

The formula for the calculation of moles is shown below:

`moles = (Mass\ taken)/(Molar\ mass)`

Thus,

`Moles= (0.1082\ g)/(204.22\ g/mol)`

`Moles= 5.2982* 10^(-4)\ mol`

According to the reaction shown below:

KHP + NaOH ⇒ KNaP + H₂O

1 mole of KHP reacts with 1 mole of NaOH

So,

`5.2982* 10^(-4)\ mol` of KHP reacts with
`5.2982* 10^(-4)\ mol` of NaOH

Moles of NaOH =
`5.2982* 10^(-4)\ mol`

Volume = 24.46 mL = 0.02446 L ( 1 mL = 0.001 L)

`Molarity=(Moles\ of\ solute)/(Volume\ of\ the\ solution)`

`Molarity_(NaOH)=(5.2982* 10^(-4))/(0.02446)`

`Molarity_(NaOH)=0.02166\ M`