Question

What is Ka for HCN(aq) H+(aq)+CN-(aq)?​

Answer 1

Answer:

c

Explanation:

Answer 2

$\tt C.~Ka=\dfrac{[H^+][CN^-]}{[HCN]}$

Further explanation  

According to Arrhenius, acids are substances which, when dissolved in water, release Hions.  

An HₓY acid in water will ionize:  

HₓY (aq) ⇒ xH⁺ (aq) + Yˣ- (aq)  

In general, the weak acid ionization reaction  

HA (aq) ⇒ H⁺ (aq) + A⁻ (aq)  

Ka's value  

$\large {\boxed {\bold {Ka \: = \: \frac {[H ^ +] [A ^ -]} {[HA]}}}}$

So for HCN

HCN(aq)⇒H⁺(aq)+CN⁻(aq)

$\tt Ka=\dfrac{[H^+][CN^-]}{[HCN]}$