what is the pH of a 1.0x10^-2M solution of HCN?

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what is the pH of a 1.0x10^-2M solution of HCN?

2007-04-01 16:58:04 · 2 answers · asked by jack g 1 in Science & Mathematics ➔ Chemistry

2 answers

HCN <> H+ + CN-
initial concentration
1 10^-2....0 .....0
at equilibrium
1 10^-2-x x .... .x

Ka = (H+)(CN-)/(HCN)= x^2/ 1 10^-2-x =4.5 10^- 4

x = concentration H+ =0.00212 M

pH = - log 0.00212 = 2.67

2007-04-02 02:19:40 · answer #1 · answered by Anonymous · 0⤊ 0⤋

It's the negative log of the root of (Ka x 0.01).

You have to look up the Ka!

2007-04-01 21:33:03 · answer #2 · answered by Gervald F 7 · 0⤊ 0⤋