(Originais Teachy 2023) - Question Very Hard of Chemistry

One of the most fascinating aspects of Chemistry is the ability to transform and exist in different states of aggregation, depending on temperature and pressure conditions. The phase diagram is a powerful tool that helps us visualize and understand these transitions. Consider a system with a pure substance that can exist in the solid, liquid, and gaseous states. Based on the provided phase diagram, answer the following questions: 1) Identify the triple point and explain its importance in the study of phase equilibria. 2) Describe the anomalous behavior of water based on its phase diagram and discuss the biological and environmental implications of this phenomenon. 3) Select a point on the diagram and justify, based on the phase equilibrium lines, in which state the substance would be if subjected to those temperature and pressure conditions.

To calculate the equilibrium quotient of a chemical reaction, it is necessary to know the concentrations of the chemical species involved at constant temperature and pressure. For example, for the combustion reaction of natural gas (CH4 + 2O2 --> CO2 + 2H2O), what would be the value of the equilibrium constant?

When studying covalent bonds, 1st-year high school students learned about Lewis theory, which describes the formation of covalent bonds through the sharing of electron pairs between atoms. Considering that the covalent bond is formed between two non-metals, propose and explain an example of a covalent compound, highlighting its structural formula and how Lewis theory can be applied to describe the formation of covalent bonds in the chosen compound. Additionally, briefly discuss a characteristic physical or chemical property of this type of covalent compound that differentiates it from ionic or metallic compounds.