(Originais Teachy 2023) - Question Medium of Chemistry

A chemical reaction A + 2B -> C + D occurs in a system where the initial concentrations of A and B are, respectively, 0.1 mol/L and 0.2 mol/L. After a period of time, the concentration of A decreased to 0.05 mol/L. Considering that the reaction is first order with respect to A and second order with respect to B, determine the overall order of the reaction and explain how you reached this conclusion.

The addition in cycloalkanes is a type of chemical reaction that occurs between two organic compounds, through the opening of an aromatic cycle. This reaction is responsible for the formation of a new compound, with the presence of a different functional group. What is the chemical equation for the addition of bromine to cyclopropane?

During a Chemistry class, a 1st-year high school student realized that the concept of mole, essential for understanding chemical reactions, could be applied in a daily life context. He decided to analyze the bread-making process to understand the importance of measuring the amount of reactants, such as yeast, to ensure the quality of the final product. Considering that 1 mole of any substance contains approximately 6.02 x 10^23 elementary entities, and knowing that biological yeast is a mixture of compressed yeast cells and starch, the student proposed the following calculation: 'If a baker uses 25 g of biological yeast to make 3 loaves of bread, and each loaf requires exactly 8 g of yeast for the dough to rise properly, what is the amount of matter, in moles, of biological yeast that the baker uses in each loaf?' Based on this information, answer: 1) What is the relationship between the mass of yeast used per loaf and the molar mass of yeast? 2) What is the practical importance, in terms of bread quality, of measuring the correct amount of yeast matter used in each loaf?