Titration Analysis Will 0.2 Mol/dm³ Nitric Acid Fully Neutralize 0.5 Mol/dm³ Sodium Hydroxide

Neutralization reactions, a cornerstone of chemistry, involve the interaction of acids and bases to form salt and water. Titration experiments are a precise method to determine the concentration of an unknown solution by reacting it with a solution of known concentration. In this comprehensive analysis, we will delve into a specific titration scenario: the reaction between 0.2 mol/dm³ nitric acid (HNO₃) and 0.5 mol/dm³ sodium hydroxide (NaOH). The central question we aim to address is whether a 50 cm³ volume of the nitric acid solution will fully neutralize an 80 cm³ volume of the sodium hydroxide solution. To answer this question, we will embark on a step-by-step calculation, examining the stoichiometry of the reaction, determining the number of moles of each reactant, and comparing their relative amounts. This exploration will provide a clear understanding of the neutralization process and allow us to definitively conclude whether the nitric acid will completely neutralize the sodium hydroxide.

Understanding Neutralization Reactions and Titration

At its core, neutralization is the reaction between an acid and a base. This reaction results in the formation of a salt and water, effectively neutralizing the characteristic properties of both the acid and the base. The driving force behind this process is the combination of hydrogen ions (H⁺) from the acid and hydroxide ions (OH⁻) from the base to form water (H₂O). This fundamental chemical process plays a vital role in various applications, from industrial processes to biological systems.

Titration serves as a precise analytical technique used to determine the concentration of a solution. In a typical titration, a solution of known concentration, termed the titrant, is gradually added to a solution of unknown concentration, the analyte. The reaction between the titrant and analyte proceeds until the reaction reaches completion, known as the equivalence point. This point is often visually indicated by a color change, facilitated by an indicator substance added to the solution. By carefully measuring the volume of titrant required to reach the equivalence point, we can accurately determine the concentration of the analyte.

The Significance of Stoichiometry in Neutralization

Stoichiometry, the study of the quantitative relationships between reactants and products in chemical reactions, is paramount in understanding neutralization reactions. The balanced chemical equation for the reaction provides crucial information about the molar ratios in which the acid and base react. For example, in the reaction between a monoprotic acid (an acid that donates one proton) and a monobasic base (a base that accepts one proton), the stoichiometric ratio is typically 1:1. This means that one mole of the acid will react completely with one mole of the base. Deviations from this ratio may occur with polyprotic acids or polybasic bases, necessitating a careful consideration of the stoichiometry to ensure accurate calculations.

Analyzing the Reaction: Nitric Acid and Sodium Hydroxide

The Chemical Equation: HNO₃ + NaOH → NaNO₃ + H₂O

The reaction between nitric acid (HNO₃), a strong acid, and sodium hydroxide (NaOH), a strong base, is a classic example of a neutralization reaction. The balanced chemical equation for this reaction is:

HNO₃ (aq) + NaOH (aq) → NaNO₃ (aq) + H₂O (l)

This equation reveals a crucial aspect of the reaction: the stoichiometric ratio between nitric acid and sodium hydroxide is 1:1. This implies that one mole of nitric acid will react completely with one mole of sodium hydroxide to produce one mole of sodium nitrate (NaNO₃), a salt, and one mole of water (H₂O).

Calculating Moles of Reactants

To determine whether the nitric acid will fully neutralize the sodium hydroxide, we must calculate the number of moles of each reactant present in the given volumes and concentrations. The number of moles (n) can be calculated using the formula:

n = Concentration (mol/dm³) × Volume (dm³)

Nitric Acid (HNO₃):

The concentration of nitric acid is 0.2 mol/dm³, and the volume is 50 cm³. We need to convert the volume from cm³ to dm³ by dividing by 1000:

Volume = 50 cm³ / 1000 cm³/dm³ = 0.05 dm³

Now, we can calculate the number of moles of nitric acid:

n(HNO₃) = 0.2 mol/dm³ × 0.05 dm³ = 0.01 moles

Sodium Hydroxide (NaOH):

The concentration of sodium hydroxide is 0.5 mol/dm³, and the volume is 80 cm³. Again, we convert the volume to dm³:

Volume = 80 cm³ / 1000 cm³/dm³ = 0.08 dm³

Now, we calculate the number of moles of sodium hydroxide:

n(NaOH) = 0.5 mol/dm³ × 0.08 dm³ = 0.04 moles

Comparing Moles and Determining the Limiting Reactant

Having calculated the number of moles of each reactant, we can now compare them to determine which reactant, if any, is the limiting reactant. The limiting reactant is the reactant that is completely consumed in the reaction, thereby determining the maximum amount of product that can be formed. In this case, since the stoichiometric ratio between nitric acid and sodium hydroxide is 1:1, the reactant with fewer moles will be the limiting reactant.

Comparing the number of moles:

n(HNO₃) = 0.01 moles n(NaOH) = 0.04 moles

It is evident that nitric acid has fewer moles (0.01 moles) compared to sodium hydroxide (0.04 moles). Therefore, nitric acid is the limiting reactant in this reaction. This means that all the nitric acid will be consumed during the reaction, while some sodium hydroxide will be left unreacted.

Conclusion: Will Nitric Acid Fully Neutralize Sodium Hydroxide?

Based on our calculations and analysis, we can now definitively answer the question: Will the 0.2 mol/dm³ nitric acid with a volume of 50 cm³ fully neutralize the 0.5 mol/dm³ sodium hydroxide with a volume of 80 cm³?

The answer is no. The nitric acid will not fully neutralize the sodium hydroxide. Since nitric acid is the limiting reactant, it will be completely consumed in the reaction. However, because there are more moles of sodium hydroxide present than nitric acid, some sodium hydroxide will remain unreacted in the solution. The resulting solution will be alkaline, with the pH greater than 7, due to the presence of excess hydroxide ions from the unreacted sodium hydroxide.

Implications and Further Considerations

This analysis highlights the importance of stoichiometry in predicting the outcome of chemical reactions. By carefully considering the molar ratios and the amounts of reactants, we can determine the limiting reactant and predict whether a reaction will proceed to completion or whether there will be an excess of one or more reactants. In practical applications, such as industrial processes or laboratory experiments, understanding the limiting reactant is crucial for optimizing reaction yields and minimizing waste.

Furthermore, this example illustrates the concept of neutralization in the context of acid-base chemistry. Neutralization reactions are fundamental to many chemical processes, and their understanding is essential for various applications, including chemical synthesis, environmental chemistry, and biochemistry. By mastering the principles of stoichiometry and neutralization, we can gain a deeper understanding of the chemical world around us.

In summary, the 50 cm³ of 0.2 mol/dm³ nitric acid will not fully neutralize the 80 cm³ of 0.5 mol/dm³ sodium hydroxide. The nitric acid is the limiting reactant, and there will be excess sodium hydroxide remaining in the solution, making it alkaline.