Question

A solid white substance \(\mathrm{A}\) is heated strongly in the absence of air. It decomposes to form a new white substance \(\mathrm{B}\) and a gas \(\mathrm{C}\) The gas has exactly the same properties as the product obtained when carbon is burned in an excess of oxygen. Based on these observations, can we determine whether solids \(\mathrm{A}\) and \(\mathrm{B}\) and the gas \(\mathrm{C}\) are elements or compounds? Explain your conclusions for each substance.

Short answer

Based on the given observations, we can conclude that solid A is a compound as it decomposes into simpler substances (solid B and gas C). Gas C is identified as carbon dioxide (CO₂), which is a compound. However, there is not enough information provided to determine whether solid B is an element or a compound.

Step-by-step solution

Understand the Decomposition Process

When a substance decomposes, it breaks down into simpler constituent substances. In the given problem, solid A decomposes into solid B and gas C. This indicates that solid A is a compound as it can be broken down into simpler substances. #Step 2: Identify Gas C#

Identify Gas C

It is mentioned that gas C has the same properties as the product obtained when carbon is burned in excess oxygen. When carbon is burned in excess oxygen, the product formed is carbon dioxide (CO₂). Therefore, gas C can be identified as carbon dioxide (CO₂), which is a compound. #Step 3: Analyze Solid B#

Analyze Solid B

Given that solid A decomposes into solid B and gas C, and since gas C is a compound (CO₂), this implies that solid A is a compound made up of atoms from solid B and CO₂. There is not enough information provided to determine whether solid B is an element or a compound. It could be either. #Step 4: Conclusions for Solid A, Solid B, and Gas C#

Conclusions for Solid A, Solid B, and Gas C

Based on the analysis in the previous steps, we can conclude the following: - Solid A: It decomposes into simpler substances (solid B and gas C) and hence, it is a compound. - Solid B: There is not enough information about this substance to determine if it is an element or a compound. - Gas C: It is identified as carbon dioxide (CO₂), which is a compound.

Key concepts

Chemical Reactions

When substances interact and produce one or more new substances, a chemical reaction has occurred. A key aspect is that the new substances formed have different properties from the original substances. In our exercise, the heating of a solid substance A in the absence of air causes a reaction that results in the creation of a new solid B and a gas C.

The indication that a chemical reaction has taken place is the change in color, the formation of a gas, or in some cases, a change in temperature or the emission of light. In educational contexts, it's crucial to recognize and classify these reactions to understand the underlying principles of chemistry. Chemical reactions are the foundation of countless natural and industrial processes, from the metabolism in our bodies to the creation of new materials. By deciphering the subtle clues in a reaction, like the properties of Gas C matching those of the combustion of carbon, students can start to draw connections and identify what compounds are involved.

Compound Identification

Identifying chemical compounds requires a keen understanding of their properties, such as physical state, color, and reaction behavior. In the decomposition reaction we're studying, solid A undergoes a chemical change when heated, producing solid B and gas C.

By observing that gas C shares properties with carbon dioxide produced by the complete combustion of carbon, one can deduce the identity of the gas. This kind of detective work is foundational to chemistry and is a potent example of how knowledge of compound properties can lead to compound identification. The science of figuring out the structure of compounds from indirect evidence is akin to solving a puzzle, where knowing the chemical behavior of substances helps piece together the mystery.

Chemical Decomposition

Chemical decomposition, also known as analysis or breakdown, is the process in which a compound is broken down into simpler compounds or its constituent elements. It's one of the most fundamental types of chemical reactions. The exercise shows us decomposition in action as solid A is heated and breaks into solid B and gas C.

Understanding Decomposition

In educational terms, understanding decomposition is vital as it relates to many aspects of chemistry, including the cycles within biology and industrial processes. For instance, photosynthesis involves the decomposition of carbon dioxide, and so does the manufacture of lime from limestone.

A deeper understanding of the types of compounds that can undergo decomposition, the energy required to trigger the reaction, and the products formed not only enriches a student's chemistry knowledge but also equips them with the ability to predict and manipulate chemical reactions for various scientific and practical applications.