Classify this solution as acidic, basic, or neutral.

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 \( \mathbf{C}=(\mathbf{1 2} \times \mathbf{9 8 . 9 3} \%)+(\mathbf{1 3 . 0 0 3 3 5} \times \mathbf{1 . 0 7} \%) \) \( =\mathbf{1 2 . 0 1} \)

\( \frac { 0.6 g \times 0.082 atm . L / mol . K \times 500 K } { 0.984 atm \times 0.5 K } \)

3. Para las reacciones redox completas que se muestran a continuación: a) divida reacción en sus semirreacciones; b) identifique el agente oxidante; c) identifique el ag reductor. a) \( 2 \mathrm{Sr}+\mathrm{O}_{2} \rightarrow 2 \mathrm{SrO} \) b) \( 2 \mathrm{Li}+\mathrm{H}_{2} \rightarrow 2 \mathrm{LiH} \) c) \( 2 \mathrm{Cs}+\mathrm{Br}_{2} \rightarrow 2 \mathrm{CsBr} \) d) \( 3 \mathrm{Mg}+\mathrm{N}_{2} \rightarrow \mathrm{Mg}_{3} \mathrm{~N}_{2} \) e) \( 4 \mathrm{Fe}+3 \mathrm{O}_{2} \rightarrow 2 \mathrm{Fe}_{2} \mathrm{O}_{3} \) f) \( \mathrm{Cl}_{2}+2 \mathrm{NaBr}^{-} \rightarrow 2 \mathrm{NaCl}+\mathrm{Br}_{2} \) g) \( \mathrm{Si}+2 \mathrm{~F}_{2} \rightarrow \mathrm{SiF} \) h) \( \mathrm{H}_{2}+\mathrm{Cl}_{2} \rightarrow 2 \mathrm{HCl} \)

(8)In which of the following solution, the concentration of acid is equal to the concentration of hydronium ion? \( \begin{array}{llll}\text { a) } \mathrm{HCN} & \text { b) } \mathrm{HCOOH} & \text { c) } \mathrm{H}_{2} \mathrm{SO}_{4} & \text { d) } \mathrm{HBr}\end{array} \)