Question

Dichlorine oxide is used as bactericide to purify water. It is produced by the chlorination of sulfur dioxide gas. SO2(g) 1 2Cl2(g) 9: SOCl2(l) 1 Cl2O(g) How many liters of Cl2O can be produced by mixing 5.85 L of SO2 and 9.00 L of Cl2? How many liters of the reactant in excess are present after reaction is complete? Assume 100% yield and that all the gases are measured at the same temperature and pressure.

Short answer

Answer: 4.50 L of Cl2O can be produced, and 1.35 L of SO2 is in excess after the reaction is complete.

Step-by-step solution

Write down the balanced chemical equation

The balanced chemical equation for the reaction is given as: SO2(g) + 2Cl2(g) → SOCl2(l) + Cl2O(g)

Calculate the moles of reactants

We know that at the same temperature and pressure, the volume ratio of the reactants is equal to the mole ratio. Therefore, we can directly use the given volumes of SO2 and Cl2 to determine their moles: Moles of SO2 = 5.85 L Moles of Cl2 = 9.00 L

Find the limiting reactant

To determine which reactant is limiting, we can use the mole ratio from the balanced equation. For every mole of SO2, we need 2 moles of Cl2 for the reaction to occur. So, in our case, we need 2 * 5.85 L = 11.70 L of Cl2 to react with 5.85 L of SO2 completely. Since we only have 9.00 L of Cl2, Cl2 is the limiting reactant.

Calculate the volume of Cl2O produced

Using the mole ratio in the balanced equation, we can calculate the volume of Cl2O produced. For every 2 moles of Cl2, 1 mole of Cl2O is produced. So, when 9.00 L of Cl2 is reacted, the volume of Cl2O produced is: 9.00 L x (1 moles of Cl2O / 2 moles of Cl2) = 4.50 L So, 4.50 L of Cl2O can be produced from the given volumes of reactants.

Calculate the volume of the reactant in excess

We already know that Cl2 is the limiting reactant, so SO2 is in excess. To calculate how much SO2 is left after the reaction, we first calculate the moles of Cl2 that reacted: 9.00 L x (1 mole of SO2 / 2 moles of Cl2) = 4.50 L of SO2 reacted Now, we subtract the moles of SO2 that reacted from the initial moles of SO2 to find the moles of SO2 in excess: 5.85 L - 4.50 L = 1.35 L So, 1.35 L of SO2 is present in excess after the reaction is complete. The final answer is that 4.50 L of Cl2O can be produced and 1.35 L of SO2 is in excess after the reaction is complete.

Key concepts

Limiting Reactant

The concept of a limiting reactant is crucial in stoichiometry, which refers to the substance in a chemical reaction that is completely consumed first, limiting the amount of product that can be formed. In our example problem, we were given the volumes of sulfur dioxide (SO2) and chlorine gas (Cl2). After performing calculations based on the balanced chemical equation, we found that chlorine gas (Cl2) was the limiting reactant.
By identifying the limiting reactant, we can predict how much product can be formed and estimate the amount of excess reactants left over. It's like a recipe – if you run out of one ingredient, you can't make any more of the dish, no matter how much of the other ingredients you have left.

Mole Volume Ratio

In stoichiometry, the mole volume ratio is a direct comparison of volumes of gases involved in a reaction at the same temperature and pressure, based on Avogadro's Law. This principle states that equal volumes of gases, at the same temperature and pressure, contain an equal number of moles. Thus, if we are given the volume of gases, like in our problem, we can use the volumes directly as if they were mole amounts.
When we used the volumes of SO2 and Cl2 given in liters, we were effectively using their mole ratios since the reaction conditions were constant. This allowed us to easily determine which reactant would be exhausted first (Cl2 in this case) without needing to convert to moles explicitly.

Chemical Reaction Yield

The yield of a chemical reaction tells us how much product is obtained compared to the maximum amount possible, which is known as the theoretical yield. In practice, yields can be less than 100% due to factors such as side reactions, incomplete reactions, or impurities. However, in our textbook example, it was assumed that the yield was 100%, which implies that all of the limiting reactant (Cl2) was converted into the desired product, Cl2O.
Understanding yields is important not only academically but also industrially, where maximizing yield can have significant economic implications. For our educational purposes, working with a 100% yield simplifies calculations, allowing students to focus on the stoichiometry without additional complexities of real-world reaction conditions.

Balanced Chemical Equation

A balanced chemical equation is the roadmap of a chemical reaction that shows the exact proportions of reactants and products. An equation must be balanced to obey the Law of Conservation of Mass, indicating that matter cannot be created or destroyed in a chemical reaction.
The balanced equation in our example was: SO2(g) + 2Cl2(g) → SOCl2(l) + Cl2O(g).This indicates that one mole of SO2 reacts with two moles of Cl2 to produce one mole of thionyl chloride (SOCl2) and one mole of dichlorine oxide (Cl2O). Balancing equations is a foundational skill in chemistry that enables students to quantify the relationships between reactants and products, perform mole-to-mole conversions, and ultimately solve stoichiometric problems effectively.