Question

When baking soda is added to a solution of sulfuric acid, the container becomes warmer to the touch. Is this an endothermic or exothermic reaction? Explain.

Short answer

The reaction between baking soda and sulfuric acid is an exothermic reaction because it releases heat into the environment, causing the container to feel warmer.

Step-by-step solution

Understand the Terms

First, know what endothermic and exothermic reactions are. In an endothermic process, energy (as heat) flows into the system from its surroundings. In an exothermic process, energy (as heat) flows out of the system into its surroundings.

Interpret the Given Information

From the fact that the container becomes warmer to the touch, this shows that heat is being released. This heat is transferred from the reaction and warms up the surroundings (the container in this case).

Identify the Reaction Type

A reaction which releases heat to the environment is termed as an exothermic reaction. Therefore, adding baking soda to a solution of sulfuric acid is an exothermic process.

Key concepts

Chemical Reactions

Chemical reactions are processes where reactants transform into products through the breaking and forming of chemical bonds. It's essential to understand that these reactions often involve energy changes, as energy is required to break bonds, and energy is released when new bonds form. Whether a reaction absorbs or releases energy determines a lot about how it will behave.

For instance, a reaction like when baking soda reacts with sulfuric acid, involves the release of energy, and therefore results in an increase in the temperature of the surroundings. The container getting warmer is a practical indication that a chemical change is underway and that this particular reaction is exothermic, as heat is 'exiting' the system. Monitoring temperature changes is a simple yet effective way to determine the nature of a chemical reaction.

Energy Transfer in Reactions

Energy transfer is integral to chemical reactions. This is because chemical bonds are forms of potential energy, and when they are made or broken, this energy is transformed and often released or absorbed in the form of heat. In an exothermic reaction, such as the reaction between baking soda and sulfuric acid, energy is transferred from the reactants to the surroundings as heat.

Understanding Energy Flow

When you touch a container that hosts an exothermic reaction and feel heat, it's the tangible evidence of energy flowing out of the system. By contrast, in an endothermic reaction, you would observe the opposite; the container would feel colder as the reaction absorbs energy from the environment. It's important to notice how the direction of energy flow indicates the type of reaction and shapes its effects on the surroundings.

Reaction Processes

The process of a chemical reaction is governed by the reactants, the conditions under which the reaction takes place, and the balance between the energy required to break the initial bonds and the energy released when new bonds form. Considering our example with baking soda and sulfuric acid, the process begins when the two substances come in contact.

Sequence of Events

The sequence starts with the reactants experiencing an initial energy investment to disrupt their stable states. This is followed by a transition phase where the reactants are converted into products, with new bonds being formed. Finally, if the overall process releases more energy than it consumes, the reaction is exothermic, and this released energy is what makes the container feel warmer. Understanding each step in this process helps in predicting outcomes and managing reaction conditions for desired results.