Скачать или смотреть Is NaCN acidic, basic, or neutral (dissolved in water)?

To tell if NaCN (Sodium cyanide) forms an acidic, basic (alkaline), or neutral solution we can use these three simple rules along with the neutralization reaction that formed NaCN .

First we need to figure out the acid and base that were neutralized to form Sodium cyanide. The equation for NaCN is:

HCN + NaOH = NaCN + H2O

It is also useful to have memorized the common strong acids and bases to determine whether NaCN acts as an acid or base in water (or if it forms a neutral solution).

Strong acids: HCl, H2SO4, HNO3, HBr, HI, HClO4
Weak acids: HF, CH3COOH, H2CO3, H3PO4, HNO2, H2SO3
Strong Bases: LiOH, NaOH, KOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
Weak Bases: NH3, NH4OH
Note that we are talking about whether NaCN is an acid, base, or neutral when dissolved in water.


Salts of strong bases and strong acids: pH will remain neutral at 7.
Salts of weak bases and strong acids: pH less than 7 (acidic).
Salts from strong bases and weak acids: pH greater than 7 (alkaline).

Based on these rules, the solution of NaCN dissolved in water is basic.

For polyprotic acids (e.g. H3PO4) it’s a bit more complicated and we need to use Ka and Kb to determine the pH of the resulting solution.

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