Steve C. answered • 08/03/15
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Steve C. Math & Chemistry Tutoring
The indicator is yellow in its acidic form (HInd) and red in its basic form (Ind-). HCl is a strong acid, while HCN is weak. For the equilibrium equation, the concentration of HCN is much higher than the cyanide concentration.
The answer to the problem is C: the reactants are favored, and HInd is stronger than HCN (the stronger acid dissociates, while the weaker does not).
Steve C.
For the equilibrium: HCN + Ind- <=> HInd + CN- , the concentrations of the reactants will be much higher than the concentrations of the products. (The solution is red because the concentration of Ind- is much higher than the concentration of HInd). Hind is an acid and Ind- is its conjugate base. HCN is an acid and CN- is its conjugate base. For the reaction, HInd reacts with CN- to form HCN and Ind- . If HCN was a stronger acid than HInd, it would react with Ind- to form HInd and CN- . It really comes down to which way the reaction goes...
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08/03/15
Mathalina S.
Thank you! I get it.
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08/03/15
Mathalina S.
08/03/15