KHP (potassium hydrogen phthalate, M_w = 204.22 g/mol, is an amphoteric salt used commonly as an acid to determine the concentration of a base solution, usually NaOH. The KHP is weighed very accurately, to 4 significant figures or to the milligram, then dissolved in water to create the analyte. A solution of NaOH is poured into the buret and is the titrant. A very careful titration is conducted to determine the endpoint. Use the following data to compute the concentration of the NaOH solution to 4 significant figures:
\textbf{Mass of KHP:  1.013 grams} (Dissolved in 100 mL of water . Think about why the amount of water does not affect the calculations).
\textbf{Volume of NaOH titrated to endpoint: 46.25 mL}
The concentration of NaOH is ____

To calculate the concentration of NaOH using the data provided, we can follow these steps:

### 1. Determine the moles of KHP used:
The molecular weight (\(M_w\)) of KHP is given as 204.22 g/mol, and the mass of KHP is provided as 1.013 grams.

The number of moles of KHP is calculated using the formula:

\[
\text{moles of KHP} = \frac{\text{mass of KHP}}{M_w}
\]

Substitute the known values:

\[
\text{moles of KHP} = \frac{1.013 \, \text{g}}{204.22 \, \text{g/mol}} = 0.004961 \, \text{mol}
\]

### 2. Understand the 1:1 molar ratio between KHP and NaOH:
In the titration, KHP reacts with NaOH in a 1:1 molar ratio. Therefore, the moles of KHP used will equal the moles of NaOH at the endpoint.

\[
\text{moles of NaOH} = \text{moles of KHP} = 0.004961 \, \text{mol}
\]

### 3. Convert the volume of NaOH to liters:
The volume of NaOH solution titrated is 46.25 mL, which needs to be converted to liters:

\[
\text{volume of NaOH in liters} = \frac{46.25 \, \text{mL}}{1000} = 0.04625 \, \text{L}
\]

### 4. Calculate the concentration of NaOH:
The concentration of NaOH is given by the formula:

\[
\text{Concentration of NaOH} = \frac{\text{moles of NaOH}}{\text{volume of NaOH in liters}}
\]

Substitute the known values:

\[
\text{Concentration of NaOH} = \frac{0.004961 \, \text{mol}}{0.04625 \, \text{L}} = 0.1073 \, \text{mol/L}
\]

### Final Answer:
The concentration of NaOH is \( \boxed{0.1073 \, \text{M}} \).

#### Why the amount of water doesn't affect the calculation:
The concentration of NaOH depends only on the moles of KHP and the volume of NaOH solution titrated. The volume of water in which the KHP is dissolved is irrelevant because it does not change the number of moles of KHP present.

Do you want more details or have any questions?

### Related Questions:
1. How does the titration endpoint affect the concentration of NaOH?
2. Why is KHP chosen for standardizing NaOH solutions?
3. What is the purpose of dissolving KHP in water before titration?
4. What indicator is commonly used in KHP-NaOH titrations, and why?
5. How would the calculation change if a different acid were used instead of KHP?

### Tip:
Always ensure that all units are consistent throughout the calculation, especially converting volumes to liters when calculating molarity.

KHP (potassium hydrogen phthalate, M_w = 204.22 g/mol, is an amphoteric salt used commonly as an acid to determine the concentration of a base solution, usually NaOH. The KHP is weighed very accurately, to 4 significant figures or to the milligram, then dissolved in water to create the analyte. A solution of NaOH is poured into the buret and is the titrant. A very careful titration is conducted to determine the endpoint. Use the following data to compute the concentration of the NaOH solution to 4 significant figures: Mass of KHP: 1.013 grams (Dissolved in 100 mL of water. Think about why the amount of water does not affect the calculations). Volume of NaOH titrated to endpoint: 46.25 mL. The concentration of NaOH is ____

Learn how to calculate the concentration of NaOH solution using titration data with KHP. The mass of KHP (1.013 g) and the volume of NaOH (46.25 mL) are provided. This step-by-step solution covers stoichiometry, molarity, and unit conversions, suitable for high school chemistry students.

Math Problem Statement

Solution

Ask a new question for Free

By Image

Math Problem Analysis

Mathematical Concepts

Formulas

Theorems

Suitable Grade Level

Related Recommendation