Química preguntas y respuestas

9. ¿Cuál es la molaridad de una solución que se prepara diluyendo a \( \mathbf{2 ~ L , ~} 12.7 \mathrm{~mL} \) de ácido sulfúrico de densidad 1.67 y \( 75 \% \) de pureza en peso 0.1623 M 0.0811 M 0.795 M 0.1413 M

9. ¿Cuál es la molaridad de una solución que se prepara diluyendo a \( 2 \mathrm{~L}, 12.7 \mathrm{~mL} \) de ácido sulfúrico de densidad 1.67 y \( 75 \% \) de pureza en peso

4. (15 Points) Draw, in Fischer projection, the following compounds: - A meso compound with the formula \( \mathrm{C}_{4} \mathrm{H}_{8} \mathrm{Br}_{2} \); - A compound with two chiral centers, one (R) and the other (S); - The mirror image of (S)-2-butanol

Question 13 ( 8 marks) Redox reactions are used widely and have a diverse range of applications. The metal aluminium is involved in numerous redox reactions that are important to society. a. Aluminium metal was first isolated when a scientist heated solid aluminium chloride, \( \mathrm{AlCl}_{3} \), with sodium metal in a platinum dish. Write a balanced chemical equation for this reaction.

3. (15 Points) Which of the following compounds are chiral? Draw only the (R) or (R.S) stereoisomer of each by carefully placing atoms or groups of atoms on wedgeldach bonds around the chiral center. a) 2,4 -dimethylheptane; b) 5-ethyl-3,3-dimethylheptane; c) cis-1,4-dichlorocyclohexane;

Xenon hexafluoride was one of the first noble gas compounds synthesized. The solid reacts rapidly with the silicon dioxide in glass or quartz containers to form liquid \( \mathrm{XeOF}_{4} \) and gaseous silicon tetrafluoride. What is the pressure in a \( 1.00-\mathrm{L} \) container at \( 25^{\circ} \mathrm{C} \) after 6.27 g of xenon hexafluoride reacts? (Assume that silicon tetrafluoride is the only gas present and that it occupies the entire volume.) Round your answer to 3 significant figures. Note: Reference the Fundamental constants table for additional information.

Exercise 3.8 Identify the anhydrides of the following acids and bases. \( \begin{array}{ll}\text { a. } \mathrm{HNO}_{3} & \text { d. } \mathrm{H}_{2} \mathrm{SO}_{4} \\ \text { b. } \mathrm{NaOH} & \text { e. } \mathrm{H}_{2} \mathrm{CO}_{3} \\ \text { c. } \mathrm{KOH} & \text { f. } \mathrm{Ba}\left(\mathrm{OH}_{2}\right.\end{array} \)

5. What are the missing products ' \( X \) '. ' \( Y \) ' and ' \( Z \) ' in the following equations? a. \( \mathrm{SO}_{2}+\mathrm{H}_{2} \mathrm{O} \rightarrow X \) b. \( \mathrm{MgO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Y} \) c. \( \mathrm{K}_{2} \mathrm{O}+\mathrm{SO}_{3} \rightarrow Z \)

A baker uses sodium hydrogen carbonate (baking soda) as the leavening agent in a banana-nut quick bread. The baking soda decomposes according to two possible reactions. Calculate the volume (in mL ) of \( \mathrm{CO}_{2} \) that forms at \( 196 .{ }^{\circ} \mathrm{C} \) and 0.926 atm per gram of \( \mathrm{NaHCO} \mathrm{O}_{3} \) by each of the reaction processes. Round each of your answers to 3 significant figures. Note: Reference the Fundamental constants table for additional information. Part 1 of 2 Reaction \( 1: 2 \mathrm{NaHCO}_{3}(\mathrm{~s}) \rightarrow \mathrm{Na}_{2} \mathrm{CO}_{3}(\mathrm{~s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{CO}_{2}(\mathrm{~g}) \) Part 2 of 2

What elements start with the letter T (periodic table)?