what is the pH if you mix 250ml of 3M HCl with 500ml of 1.5M CN-?
i know that:
HCl+CN- ---> HCN+Cl-
250ml converts to .75 moles and 500ml also converts to .75 moles when using the 3M and the 1.5M.
Ka=X^2/m-x
x/1000=.015/750
.02 CN- left.
2.5*10^5=x^2/(.02-x)
2.5*10^5(x^2/(.02-x))
0=x^2+(2.5*10^-5x)-(.5*10^-6)
x=.695*10^-3 [OH-]
4.0*10^-10=x^2/1-x
.75/750=x/1000
0=x^2+94.0*10^-10x)-(4.0*10^-10)
x=1.99*10^-5 [H3O+]
(.695*10^-3)-(1.99*10^-5)
1*10^-14=((6.751*10^-4)[OH-])/([H3O+](6.751*10^-4))
from there i'm stuck.