Determining the Limiting Reactant in the Reaction Between Copper(II) Oxide and Nitric Acid

Introduction

Understanding the concept of limiting reactants is crucial for chemical reactions, especially when calculating the amount of products formed. This article will guide you through the process of determining the limiting reactant in the reaction between copper(II) oxide (CuO) and nitric acid (HNO3). We will perform a step-by-step analysis and provide a detailed explanation with calculations.

Chemical Reaction and Balanced Equation

Let's consider the reaction between copper(II) oxide (CuO) and nitric acid (HNO3). The balanced chemical equation for this reaction is:

CuO 2HNO3 → Cu(NO3)2 H2O

Step 1: Calculate the Moles of Each Reactant

To determine the limiting reactant, we need to calculate the moles of each reactant first.

Moles of Copper(II) Oxide (CuO)

The molar mass of CuO is:

Molar mass of CuO 63.55 g/mol (Cu) 16.00 g/mol (O) 79.55 g/mol

Moles of CuO mass / molar mass 7.0 g / 79.55 g/mol ≈ 0.0880 moles

Moles of Nitric Acid (HNO3)

The concentration of nitric acid is 0.20 M and the volume is 50 mL (0.050 L).

Moles of HNO3 concentration × volume 0.20 mol/L × 0.050 L 0.010 moles

Step 2: Determine the Stoichiometric Requirements

From the balanced equation, we know that 1 mole of CuO reacts with 2 moles of HNO3. This means that the required moles of HNO3 for the available moles of CuO are calculated as follows:

Moles of HNO3 required 2 × moles of CuO 2 × 0.0880 moles 0.176 moles

Step 3: Compare Available Moles with Required Moles

We have:

Available moles of HNO3 0.010 moles

Required moles of HNO3 0.176 moles

Since we have a much smaller amount of HNO3 (0.010 moles) compared to the required amount (0.176 moles), HNO3 is the limiting reactant. This means that completely HNO3 will be consumed, and CuO will remain in excess.

Conclusion

The limiting reactant in the reaction between copper(II) oxide and nitric acid is nitric acid (HNO3). The calculation shows that only a fraction of the copper(II) oxide will react due to the limited amount of nitric acid.

To summarize, we used the balanced chemical equation, calculated the moles of each reactant, and compared the available and required moles to determine that nitric acid is the limiting reactant. This understanding is essential for predicting the outcomes of chemical reactions and optimizing industrial processes.