8. Albalancear la siguiente ecuación : \( \mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+\mathrm{H}_{2} \mathrm{~S}+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow \mathrm{~K}_{2} \mathrm{SO}_{4} \) \( +\mathrm{Cr}_{2}\left(\mathrm{SO}_{4}\right)+\mathrm{S}+\mathrm{H}_{2} \mathrm{O} \); calcular la suma de coeficientes del agente oxidante, agente reductor y el agua. \( \begin{array}{lll}\text { a) } 8 & \text { b) } 11 & \text { c) } 9 \\ \text { d) } 5 & \text { e) } 12 & \end{array} \)

\( \mathrm{pOH}=2.1 \) Express your answer using one decimal place.

Example Naturally occurring chlorine consists of \( 75.77 \% \) chlorine-35 atoms (mass 34.97 amu ) and \( 24.23 \% \) chlorine-37 atoms (mass 36.97 amu ). Calculate its atomic mass.

Atomic weight \( (\mathbf{A W})=\sum \) isotopic mass \( \times \) aboundance \( \cdot \) Naturally occurring carbon comprises \( \mathbf{9 8 . 9 3 \%} \%{ }^{12} \mathrm{C} \) and \( \mathbf{1 . 0 7 \%}{ }^{13} \mathrm{C} \). The masses of these isotopes are \( \mathbf{1 2} \) amu \( ( \) exactly and \( \mathbf{1 3 . 0 0 3 3 5} \mathrm{amu} \), respectively, making the atomic weight of carbon. The atomic weights of the elements are listed in the periodic table. atomic weight of \( \mathbf{C}=(\mathbf{1 2})(\mathbf{0 . 9 8 9 3})+(\mathbf{1 3 . 0 0 3 3 5})(\mathbf{0 . 0 1 0 7})=\mathbf{1 2 . 0 1} \) atomic weight of \( \mathbf{C}=(\mathbf{1 2} \times \mathbf{9 8 . 9 3} \%)+(\mathbf{1 3 . 0 0 3 3 5} \times \mathbf{1 . 0 7} \%) \) \( =\mathbf{1 2 . 0 1} \)

Classify this solution as acidic, basic, or neutral.

\( \mathrm{pOH}=7.0 \) Express your answer using one decimal place.