How Many Tablespoons of Baking Soda Are Needed to Neutralize 1 Cup of 9 N HCl?

Introduction

The neutralization of acids is a common process in chemistry, with hydrochloric acid (HCl) being a prevalent acid used in various applications. If you have 1 cup (250 grams) of a 9 normality (N) HCl solution and need to neutralize it, what amount of sodium bicarbonate (baking soda) is required? This article will delve into the chemical reaction, calculations, and important considerations.

Chemical Reaction

The chemical reaction between sodium bicarbonate (NaHCO3) and hydrochloric acid (HCl) can be described as follows:

NaHCO3 HCl → NaCl H2O CO2

According to the stoichiometry of this reaction, one mole of NaHCO3 reacts with one mole of HCl. This is a 1:1 molar ratio.

Calculations

To determine the amount of sodium bicarbonate needed to neutralize 1 cup (250 grams) of a 9 N HCl solution, follow these steps:

Step 1: Determine the mass of HCl

1 cup of 9 N HCl is approximately 250 grams. Since HCl has a molar mass of 36.5 grams per mole, we can calculate the mass of HCl as follows:

1 cup HCl 250 grams × 0.09 (normality) 22.5 grams

Step 2: Establish the ratio of NaHCO3 to HCl

The molar mass of NaHCO3 is 84 grams per mole. Using the ratio of 1:1, we can calculate the amount of NaHCO3 required to neutralize 22.5 grams of HCl.

X ———— 22.5

84 ———— 36.5

X 51.78 grams NaHCO3

Step 3: Convert grams to tablespoons

A tablespoon of sodium bicarbonate is approximately 15 grams. Therefore, the number of tablespoons needed is:

Tablespoons 51.78 / 15 ≈ 3.45 tablespoons

Important Considerations

Warning: Using sodium bicarbonate to neutralize an acid produces a significant amount of carbon dioxide gas. Be cautious and proceed slowly to avoid a hazardous situation. Mixing 1 cup of a 9 N HCl solution with 20 cups of water can dilute the HCl to a safer concentration, similar to stomach acid, which your pipes are likely to handle.

Gas Production: The reaction produces about 18 liters of carbon dioxide gas at room temperature. Thus, thorough ventilation is essential.

Conclusion

In summary, to neutralize 1 cup of a 9 normality HCl solution, you would need approximately 3.5 tablespoons of baking soda. Keep safety in mind and proceed with caution to ensure a safe and effective neutralization process.

Additional Resources

For more detailed information, refer to the following resources:

Hydrochloric Acid Sodium Bicarbonate Stoichiometry