For example, Hw question HCLO is a weak acid (Ka = 4.0e^-8) and so the salt NaCLO acts as a weak base. What is the Ph of a solution that is 0.088M in NaCLO at 25C?
How does one derive the chemical equation in order to find the concentration level to then find the ph?
Chemical Equations
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Re: Chemical Equations
Since Na is a spectator ion, it can be ignored because it won't affect the pH: NaClO + H2O(l) -> ClO- + Na+ + H2O(l)
(You would just need to convert the moles of NaClO to ClO-, which should be straightforward since they have the same coefficients in the equation.)
Now that we have ClO- isolated, we can proceed with the typical B + H2O(l) <-> OH- + BH+.
ClO- +H2O(l) <-> HClO + OH-.
From there you can set up the ICE table and find the concentration of OH, and derive the pH from it.
(You would just need to convert the moles of NaClO to ClO-, which should be straightforward since they have the same coefficients in the equation.)
Now that we have ClO- isolated, we can proceed with the typical B + H2O(l) <-> OH- + BH+.
ClO- +H2O(l) <-> HClO + OH-.
From there you can set up the ICE table and find the concentration of OH, and derive the pH from it.
Re: Chemical Equations
I find it is helpful for problems like this to always translate the problem into the general equations for an acid (HA + H2O -- H30+ + A-) and base (B + H20 --- BH+ + OH-). This helps prevent me from getting confused about the role of spectator ions and focus on the concentrations that are actually necessary for my ICE tables.
Re: Chemical Equations
In a general aspect, to derive the chemical equation for concentration, balance the number of atoms and charge in the reactants and products. Then, use the molarity formula (moles of solute per liter of solution) to find concentration, which can be used to calculate pH.
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