# What is the poh of an aqueous solution at 250 c that contains 398 109 m hydroxide ion

## Introduction

The pH of aqueous solutions measures the concentration of hydroxide ions in the solution. The higher the concentration of hydroxide ions, the higher the pH.

pH is measured on a scale from 0 to 14, with 0 being the most acidic and 14 being the most basic. A solution with a pH of 7 is neutral.

Aqueous solutions with a pH less than 7 are said to be acidic, while those with a pH greater than 7 are basic or alkaline.

The pH of an aqueous solution at 250 C that contains 398 109 m hydroxide ion would be 13.

## What is the pH of an Aqueous Solution?

### Aqueous solutions

pH is a scale used to measure the acidity or basicity of a solution. The pH of a solution is the negative logarithm of the hydronium ion concentration. The pH scale ranges from 0 to 14, with 0 being the most acidic, 7 being neutral, and 14 being the most basic.

Aqueous solutions can be classified as acidic, basic, or neutral depending on their pH. Acidic solutions have a pH below 7, while basic solutions have a pH above 7. Neutral solutions have a pH of 7.

The pH of an aqueous solution at 250 c that contains 398 109 m hydroxide ion is 9.

### The pH scale

The pH scale is a guide used to measure how acidic or basic a solution is. The pH scale ranges from 0-14, with 0 being the most acidic and 14 being the most basic. A solution with a pH of 7 is considered neutral.

pH is important because it affects how substances dissolve in water and how they interact with other substances. For example, some medications need to be taken with water that has a specific pH in order for them to work properly.

The pH of an aqueous solution can be measured using a pH meter. To find the pH of an aqueous solution, the electrode of the pH meter is placed in the solution and a reading is taken. The reading will be between 0 and 14, with 0 being the most acidic and 14 being the most basic.

### The relationship between pH and concentration

The pH of an aqueous solution is a measure of the concentration of hydrogen ions in the solution. The pH scale is logarithmic, so each unit increase in pH corresponds to a tenfold decrease in the hydrogen ion concentration. The pH of a solution with a hydrogen ion concentration of 1 molar (M) is 1, while the pH of a solution with a hydrogen ion concentration of 0.1 M is 2. The pH of a solution with a hydrogen ion concentration of 0.01 M is 3, and so on.

At 25°C, the equilibrium constant for water dissociation is 10-14. This means that the concentration of hydrogen ions in pure water is 10-7 M. The pH of pure water is therefore 7.

The relationship between pH and concentration can be expressed as follows:

pH = -log[H+]

where [H+] is the hydrogen ion concentration in moles per liter (mol/L).

## How to Measure pH

The pH of a solution is a measure of the acidity or basicity of the solution. It is measured on a scale from 0 to 14, with 7 being neutral. A pH less than 7 is acidic, and a pH greater than 7 is basic.

### pH meters

A pH meter is a scientific instrument that measures the hydrogen-ion activity in water-based solutions, indicating its acidity or alkalinity expressed as pH. The pH meter measures the difference in electrical potential between a pH electrode and a reference electrode, and converts this difference into a pH value on a scale from 0 to 14.

The first pH meter was invented by Danish chemist Sørensen in 1909. Since then, various designs of pH meters have been developed to suit different applications. Today, there are many different types of pH meters available on the market, from simple hand-held meters to more sophisticated bench-top or laboratory instruments.

pH meters are used in many different industries and applications, such as environmental monitoring, quality control in food and beverage industry, agriculture, aquaculture, and pharmaceuticals.

### pH paper

PH paper is a type of paper that is used to test the acidity or alkalinity of a solution. The pH scale is a measure of how acidic or basic a solution is. It ranges from 0 to 14, with 0 being the most acidic and 14 being the most basic. A pH of 7 is neutral.

To use pH paper, you will need to dip the paper into the solution you are testing. The paper will change color based on the acidity or alkalinity of the solution. You can then compare the color of the paper to a chart to determine the pH of the solution.

### pH indicator solutions

Phenol red is an organic compound with the formula C₁₀H₁₉NO₃S. It is a red powder that is soluble in water and alcohol, and it is used as a pH indicator. When phenol red is mixed with an aqueous solution, it changes color depending on the pH of the solution. For example, phenol red changes from yellow to orange in solutions with a pH of 4.6 or lower, and it changes from orange to red in solutions with a pH of 6.2 or higher.

## Conclusion

The poh of an aqueous solution at 250 c that contains 398 109 m hydroxide ion is 10.