Question

Consider the following equilibrium:

⇌ Fe[CN]₆³⁻(aq) + 6H₂O(l)

John was trying to prepare his famous tye-dyed t-shirts. He knows that he can control the cyanide concentration in solution by using the complex ion and his knowledge of equilibrium. To get the most intense colors, he needs more cyanide in solution. The equilibrium above is exothermic as written.

Explain whether John should make his shirts in hot or cold water.

Explain why controlling the pH of the solution would help/hurt John’s art project.

Why would John smell almonds at low pH?

Answer 1

[Fe(H2O)6]³⁺(aq) + 6CN^–(aq) <------------------------->    [Fe(CN)6]^3–(aq)   +   6H2O(l)   , DH = -Ve

1) John should make his shirts cold water. becuase forward reaction is exothermic . so exothermic reactions are favourable at low temperatures . so to get more color low temperature must be used

2) help ;

at high pH [Fe(CN)6]^3– fromation decreases because cojugate base CN- readily react with Na+ speciecs present in base . so the availability of CN - decreases

3) low pH the smell due to