Calculating the Remaining Volumes of Reactants After a Chemical Reaction

Introduction to Chemical Reactions and Stoichiometry

In chemistry, understanding the relationship between the volumes of reactants and the products formed is crucial, especially in laboratory settings. This article sheds light on how to determine the volumes of reactants remaining after a reaction between hydrogen gas (H2) and oxygen gas (O2).

Reaction of Hydrogen and Oxygen Gas

The balanced chemical equation for the reaction between hydrogen and oxygen to form water is given as:

2H2(g) O2(g) → 2H2O(l)

This equation tells us that two volumes of hydrogen gas react with one volume of oxygen gas to form two volumes of water.

Given Volumes and Stoichiometric Ratio

Initially, we are given that 60 cm3 of H2 and 50 cm3 of O2 are mixed and react. Let's break down the steps to determine the volumes of each gas remaining after the reaction.

Step 1: Determine the Stoichiometric Ratio

According to the balanced equation, 2 volumes of H2 react with 1 volume of O2. Therefore, the stoichiometric ratio is 2:1.

Step 2: Calculate the Required Volume of O2

Using the given volume of H2, we can determine how much O2 is required:

VO2 (frac{60 , text{cm}^3}{2} 30 , text{cm}^3)

Step 3: Compare Required and Available Volumes of O2

The volumes are as follows:

VO2 available 50 cm3 VO2 required 30 cm3

Since the volume of O2 available is more than the required volume, H2 is the limiting reactant.

Step 4: Calculate the Volume of H2 Reacted

According to the stoichiometric ratio, 60 cm3 of H2 will react with 30 cm3 of O2.

Step 5: Calculate the Remaining Volume of H2

Since all 60 cm3 of H2 will react:

VH2 remaining 60 cm3 - 60 cm3 0 cm3

Step 6: Calculate the Remaining Volume of O2

The volume of O2 that reacted is 30 cm3:

VO2 remaining 50 cm3 - 30 cm3 20 cm3

Conclusion

After the reaction is complete, the volumes left are:

Volume of H2 left: 0 cm3 Volume of O2 left: 20 cm3

Thus, the final answer is:

Volume of H2 left: 0 cm3 Volume of O2 left: 20 cm3

Understanding these calculations is fundamental in chemistry as it helps to predict the outcome of reactions and the amount of reactants and products involved.