(Originais Teachy 2023) - Question Medium of Chemistry

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?

Identify the organic function present in the ester of molecular formula C4H8O2 that is responsible for the aroma of a fruit. Consider that the ester has a carbon chain of 3 carbon atoms and a radical from a monocarboxylic acid of general formula CnH2nO2. Name the monocarboxylic acid and the alcohol used in the synthesis of this ester, following the IUPAC nomenclature rules for organic compounds. Justify the choice of the acid and the alcohol based on the structure and the desired aroma.

Nitro compounds are organic compounds that have one or more nitro groups (NO2) directly attached to a carbon atom of an alkyl or aryl group. They are commonly used as explosives due to their ability to rapidly decompose and release gases. Considering the IUPAC nomenclature rules for nitro compounds, answer: a) What is the correct nomenclature for the compound CH3CH2NO2? b) Write the molecular structure of 2,4-dinitrotoluene and identify the functional groups present in the molecule. c) According to the IUPAC rules, what is the name of the organic compound formed by substituting the three hydrogens of methane with three nitro groups?