Diluting a Sodium Hydroxide (NaOH) Solution: A Guide

Introduction

Sodium hydroxide (NaOH) is a highly corrosive and strong base that is commonly used in various industrial and laboratory applications. In this article, we will explore how to dilute a 4M NaOH solution by a factor of 10. This process involves understanding the concentration of the original solution and using the appropriate ratio of water to achieve the desired concentration.

Understanding the Concentration of NaOH

A 4M (molar) solution of NaOH means that there are 4 moles of NaOH per liter of solution. Before we dilute the solution, we first need to understand its initial concentration.

Calculating the Required Amount of Water

The problem states that you need to dilute a 4M NaOH solution by a factor of 10. This means that the concentration of the final solution should be 0.4M (4/10 mol/L).

Ratio of Water to Solution

To dilute a solution by a factor of 10, you need to add 9 parts of water to 1 part of the original solution. This is calculated as follows:

1 part original solution 9 parts water total 10 parts dilution

Application to the Given Scenario

In the given scenario, you have 2 liters of 4M NaOH solution. To achieve a 0.4M (40 mM) solution, you need to add enough water to make a total volume of 20 liters.

Calculation Steps

Let's break down the steps to dilute 2 liters of 4M NaOH:

Calculate the total volume after dilution: 2 liters (original solution) * 10 (dilution factor) 20 liters (total volume). Subtract the original volume from the total volume to find the volume of water needed: 20 liters (total volume) - 2 liters (original solution) 18 liters of water. Now, add 18 liters of water to the 2 liters of 4M NaOH to achieve a final concentration of 0.4M NaOH.

Safety Precautions

When dealing with concentrated solutions of NaOH and performing dilution, safety should be the top priority:

Gloves: Always wear safety gloves to protect your hands from the corrosive properties of NaOH. Goggles: Protective goggles should be worn to safeguard your eyes. Hood: Ensure you have adequate ventilation and a lab hood if necessary. Avoid splashing: Use appropriate containers to minimize splashing and accidental exposure.

Tips for Successful Dilution

To ensure the most accurate dilution process:

Ensure purity of water: Use distilled or deionized water to avoid unwanted contaminants. Mix thoroughly: After adding the water, mix the solution well to ensure that the NaOH is evenly distributed. Calibrate your measuring equipment: Use calibrated measuring tools to avoid errors in volume. Use appropriate containers: Use appropriate beakers or containers that can hold the extended volume after dilution.

Conclusion

Diluting a 4M NaOH solution by a factor of 10 is a straightforward process once you understand the concentration and the ratio of water to the original solution. By following the steps outlined in this guide, you can safely and effectively achieve the desired concentration. Always remember to prioritize safety when working with strong bases like NaOH.