(Originais Teachy 2023) - Question Hard of Sciences

What are the problems caused by the standardization of crops?

Natural phenomena can be considered as extremely important events for our planet, as they influence the climate and the life of the species that exist on it. For example, rains are necessary to keep the rivers and lakes full and thus ensure drinking water for all living beings that depend on it to survive. Which of the following is an example of a natural phenomenon that contributes to the balance of the Earth?

Explain what is the relationship between frequency and wavelength and how this affects the propagation of sound and light waves. Then, provide examples of everyday situations where this can be observed and discuss the importance of these waves in our communication and daily life.

In the solutions used in laboratories, the concentrations of ions $$\mathrm{H}_{3} \mathrm{O}^{+}$$ are usually small and a simple way to express the hydrogenionic concentration of a solution is through pH. Solutions of weak acids and bases present, in solution, an equilibrium between the various particles and, in this case, we have the equilibrium constant, that is, the ionization constant. A solution of $$1.10^{-3} \mathrm{mol}^{-1}$$ of bromoacetic acid $$\left(\mathrm{BrCH}_{2} \mathrm{CO}_{2} \mathrm{H}\right)$$ has an ionization constant equal to $$6.3.10^{-5} \mathrm{e}$$ and a solution of $$1.10^{-3} \mathrm{mol}^{-1}$$ of 4-chlorobenzoic acid $$\left(\mathrm{ClC}_{6} \mathrm{H}_{4} \mathrm{CO}_{2} \mathrm{H}\right)$$ has an ionization constant of $$1.0.10^{-4}$$. Given the following statements, I. 4-chlorobenzoic acid has a higher $$\mathrm{pH}$$ than bromoacetic acid. II. Bromoacetic acid is weaker than 4-chlorobenzoic acid. III. Since the concentrations are equal, both acids have the same $$\mathrm{pH}$$. IV. Bromoacetic acid has a higher $$\mathrm{pH}$$ than 4-chlorobenzoic acid. v. 4-chlorobenzoic acid is weaker than bromoacetic acid. It is verified that only ii and iv are correct.