h) Si en una neutralización hace reaccionar 35 mL de \( \mathrm{HClO}_{4} \) con \( 28,3 \mathrm{~mL} \) de \( \mathrm{KOH} 0,20 \mathrm{M} \), ¿Cuál es la concentración del \( \mathrm{HClO}_{4} \) Puntaje: 0,3 fórmula, 0,3 reemplazo, 0,4 resultado si no coloca la unidad ( \( -0,2 \) ) (1,0 puntos)

Which of the following molecule(s) have lone pair electrons and/or non-identical central bonds? \( \mathrm{CCl}_{4} \) \( \mathrm{CHCl}_{3} \) \( \mathrm{SO}_{3} \) \( \mathrm{CO}_{2} \mathrm{O} \)

If an endothermic reaction is at equilibrium, how will the equilibrium shift when heat is added to the reaction? View Available Hint(s) The reaction will shift toward the reactants. The reaction will shift toward the products. The reaction will not shift toward products or reactants. The reaction will shift toward both reactants and products.

The pH scale for acidity is defined by \[ \mathrm{pH}=-\log \left[\mathrm{H}^{+}\right] \] where \( \left[\mathrm{H}^{+}\right] \)is the concentration of hydrogen ions measured in moles per liter (M). a) A sample of rhubarb is found to have a hydrogen concentration of 0.000501 M . What is the pH? Round your answer to 2 decimal places. \( \mathrm{pH}=\square \) b) The pH of a sample of red onion is 5.40 . What is the hydrogen concentration? Keep at leost 2 non-zero decimal ploces. \( \left[\mathrm{H}^{*}\right]=\square \)

\[ \mathrm{Fe}_{2} \mathrm{O}_{3}(\mathrm{~s})+2 \mathrm{Al}(\mathrm{s}) \rightleftharpoons \mathrm{Al}_{2} \mathrm{O}_{3}(\mathrm{~s})+2 \mathrm{Fe}(\mathrm{s}) \] View Available Hint(s) The equilibrium will shift toward the reactants. The equilibrium will shift toward the products. The reaction will not shift toward either the products or reactants. The reaction will shift toward both the reactants and products.

Which of the following represent a buffer system? Check all that apply. \( \square \mathrm{NaOH} \) and NaCl \( \square \mathrm{H}_{2} \mathrm{CO}_{3} \) and \( \mathrm{NaHCO}_{3} \) HF and KF KCl and NaCl