Q 83. What Product Forms When Acetylene (C₂H₂) Reacts With Chlorine (Cl₂) In The Presence Of Light? Options: A. Ethane B. 1,1-Dichloroethene C. 1,2-Dichloroethene D. Chloroethane Q 84. If 10 G Of Butene (C₄H₈) Undergoes Complete Combustion, How Much Carbon Dioxide And Water Are Produced?

Introduction

Chemistry, the science that delves into the composition, structure, properties, and reactions of matter, is a fascinating field that underpins our understanding of the world around us. Within the vast realm of chemistry, organic chemistry stands out as the study of carbon-containing compounds, the very building blocks of life. In this comprehensive exploration, we will embark on a journey to unravel two intriguing chemical scenarios: the reaction of acetylene with chlorine in the presence of light and the complete combustion of butene. By delving into the intricacies of these reactions, we will gain a deeper appreciation for the fundamental principles that govern chemical transformations. Understanding these principles is crucial for students, researchers, and anyone with a passion for chemistry.

Q 83. Unraveling the Reaction of Acetylene with Chlorine: A Deep Dive

To begin our exploration, let's dissect the first chemical puzzle: the reaction of acetylene (C₂H₂) with chlorine (Cl₂) in the presence of light. Acetylene, a simple alkyne characterized by its triple bond between two carbon atoms, is a highly reactive molecule. Chlorine, a halogen, is also known for its reactivity, readily participating in chemical reactions. The presence of light acts as a catalyst, providing the energy needed to initiate the reaction. The reaction between acetylene and chlorine is a classic example of an addition reaction, where atoms or groups of atoms add to a molecule, typically at a multiple bond. In this case, the triple bond in acetylene is susceptible to attack by chlorine molecules.

When acetylene and chlorine react in the presence of light, a series of addition reactions occur. Initially, one chlorine molecule adds across the triple bond, transforming it into a double bond. This intermediate product is dichloroethene, which exists as two isomers: 1,1-dichloroethene and 1,2-dichloroethene. The reaction doesn't stop here; another chlorine molecule can add across the double bond in dichloroethene, leading to the formation of tetrachloroethane. The specific product formed depends on the reaction conditions, such as the ratio of reactants and the intensity of light. However, under typical conditions, the major products are a mixture of dichloroethene isomers. Therefore, the correct answer to the question is a combination of options B and C, 1,1-dichloroethene and 1,2-dichloroethene. To fully grasp this reaction, it's essential to understand the concept of electrophilic addition, where chlorine acts as an electrophile, attacking the electron-rich triple bond of acetylene. The reaction proceeds through a series of steps, involving the formation of carbocations and the addition of chloride ions. The stability of the carbocations influences the regiochemistry of the reaction, determining which isomer of dichloroethene is predominantly formed. This reaction highlights the versatility of acetylene as a building block in organic synthesis, as it can be transformed into a variety of chlorinated compounds. Furthermore, it underscores the importance of reaction conditions in dictating the outcome of a chemical transformation.

Q 84. Decoding the Combustion of Butene: A Stoichiometric Journey

Now, let's turn our attention to the second chemical scenario: the complete combustion of butene (C₄H₈). Butene, an alkene with a double bond between two carbon atoms, is a flammable hydrocarbon. Combustion, a chemical process involving the rapid reaction between a substance with an oxidant, usually oxygen, is an exothermic reaction, meaning it releases heat and light. Complete combustion occurs when there is an excess of oxygen, leading to the formation of carbon dioxide (CO₂) and water (H₂O) as the primary products. Understanding combustion reactions is crucial in various fields, including energy production and environmental science.

To determine the amount of products formed during the complete combustion of 10 g of butene, we need to embark on a stoichiometric journey. Stoichiometry, the branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions, provides the tools to calculate the amounts of substances involved in a chemical reaction. The first step in this journey is to write a balanced chemical equation for the combustion of butene. The balanced equation is:

C₄H₈ + 6O₂ → 4CO₂ + 4H₂O

This equation tells us that one mole of butene reacts with six moles of oxygen to produce four moles of carbon dioxide and four moles of water. The next step is to calculate the number of moles of butene in 10 g. To do this, we need the molar mass of butene, which is 56.11 g/mol. Using the formula:

Moles = Mass / Molar mass

We find that 10 g of butene is equal to 0.178 moles. Now, using the stoichiometry of the balanced equation, we can determine the number of moles of carbon dioxide and water produced. Since one mole of butene produces four moles of carbon dioxide and four moles of water, 0.178 moles of butene will produce:

0. 178 moles butene * (4 moles CO₂ / 1 mole butene) = 0.712 moles CO₂
1. 178 moles butene * (4 moles H₂O / 1 mole butene) = 0.712 moles H₂O

Finally, to convert these moles to grams, we multiply by the respective molar masses:

0. 712 moles CO₂ * (44.01 g/mol) = 31.33 g CO₂
1. 712 moles H₂O * (18.015 g/mol) = 12.83 g H₂O

Therefore, the complete combustion of 10 g of butene produces 31.33 g of carbon dioxide and 12.83 g of water. This calculation demonstrates the power of stoichiometry in predicting the outcome of chemical reactions. Understanding the quantitative relationships between reactants and products is essential for various applications, including industrial chemical processes and environmental monitoring. The combustion of butene also highlights the importance of balancing chemical equations, as it ensures that the law of conservation of mass is obeyed. This law states that matter cannot be created or destroyed in a chemical reaction, meaning the total mass of the reactants must equal the total mass of the products.

Exploring Reaction Mechanisms and Factors Influencing Reactions

Beyond the specific examples of acetylene chlorination and butene combustion, it's crucial to delve into the broader concepts of reaction mechanisms and factors that influence chemical reactions. A reaction mechanism is a step-by-step description of how a chemical reaction occurs, detailing the sequence of elementary reactions that lead from reactants to products. Understanding reaction mechanisms allows us to predict the products of a reaction, optimize reaction conditions, and design new chemical transformations. For instance, the chlorination of acetylene proceeds through a mechanism involving electrophilic attack of chlorine on the triple bond, followed by the formation of carbocations and the addition of chloride ions. Knowing this mechanism helps us understand why certain products are favored over others and how to control the reaction selectivity.

Several factors can influence the rate and outcome of a chemical reaction, including temperature, concentration, catalysts, and the nature of the reactants and solvents. Temperature affects the kinetic energy of molecules, with higher temperatures leading to more frequent and energetic collisions, thus increasing the reaction rate. Concentration influences the probability of collisions between reactant molecules, with higher concentrations generally leading to faster reactions. Catalysts are substances that speed up a reaction without being consumed in the process, by providing an alternative reaction pathway with a lower activation energy. The nature of the reactants and solvents also plays a crucial role; for example, polar solvents can stabilize charged intermediates, influencing the reaction mechanism and rate.

Applications and Implications in the Real World

The chemical reactions we've explored have far-reaching applications and implications in the real world. The chlorination of acetylene is used in the production of chlorinated solvents and polymers, which have various industrial applications. However, it's important to note that some chlorinated compounds are environmentally harmful, and their use is being phased out in favor of more sustainable alternatives. The combustion of hydrocarbons like butene is a fundamental process in energy production, powering vehicles, generating electricity, and heating homes. However, the combustion of fossil fuels also releases greenhouse gases, such as carbon dioxide, which contribute to climate change. Therefore, developing cleaner and more efficient combustion technologies and exploring alternative energy sources are crucial for mitigating the environmental impact of energy production.

Conclusion

In conclusion, our exploration of the reaction of acetylene with chlorine and the combustion of butene has provided a glimpse into the fascinating world of chemistry. We've delved into the intricacies of these reactions, uncovering the underlying principles that govern chemical transformations. From understanding reaction mechanisms to applying stoichiometry, we've gained valuable insights into the behavior of molecules and the factors that influence chemical reactions. The knowledge and skills acquired in this exploration are essential for anyone pursuing a career in chemistry or related fields. Moreover, the broader implications of these reactions in areas such as industrial chemistry, energy production, and environmental science highlight the importance of chemistry in addressing global challenges. By continuing to explore the wonders of chemistry, we can unlock new possibilities and create a better future for all.