Calculating pH of 0.140M NaOCN Solution - Ka HOCN=3.5x10^-4

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To calculate the pH of a 0.140M NaOCN solution, the dissociation constant (Ka) for HOCN is given as 3.5x10^-4. Since OCN- is the conjugate base of HOCN, Kb can be calculated using the relationship Kb = Kw/Ka, where Kw is 1.0x10^-14. The concentration of OCN- is approximately 0.140M, allowing for the simplification of the equation to Kb = x^2/0.140. After calculating Kb, pOH can be determined, which can then be converted to pH using the relation pH + pOH = 14. The final pH value can be derived from these calculations.
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what is the pH of a 0.140M NaOCN solution? ka HOCN=3.5x10^-4
(rule of 100 can simplify 0.140-x to 0.140)

i know that ka=HOCN*OH^-/OCN^-=x^2/0.140
but i don't know the left hand side...i don't know what to do with HOCN=3.5x10^-4..
 
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OCN- is a weak, conjugate base of HOCN. Calculate Kb, calculate pOH from known Kb and concentration, convert to pH.

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Thread 'Confusion regarding a chemical kinetics problem'

Thread 'Confusion regarding a chemical kinetics problem'

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