Question

which has highest ph
(1) CH3COOK
(2) NA2CO3
(3) NH4CL
(4) NANO3 ​

Answer 1

Correct question :-

which has highest ph

(1) CH$_3$COOK

(2) Na$_2$CO$_3$

(3) NH$_4$Cl

(4) NaNO$_3$

AnSwer :-

Option (2) Na$_2$CO$_3$ is correct.

Explaination :-

pH is inversely proportional to Hydrogen ion concentration. As the Concentration of H$^{+}$ decrease.

$\sf pH = log\dfrac{1}{[{H}^{+}]}$

$\Large \star$pH increase Amonium Chloride (NH$_4$Cl) is a salt of weak base and strong acid .so, it's aqueous solution will be acidic as

$\sf NH_4Cl + H_2O \longrightarrow NH_4OH + HCl$

So, pH of NH$_4$Cl is less than 7

$\Large \star$Sodium nitrate (NaNO$_3$) is the Salt of strong acid and strong base. So it's aqueous solution is neutral as

$\sf NaNO_3 + H_2O \longrightarrow NaOH + HNO_3$

So, pH of NaNO$_3$ is 7.

$\Large \star$Potassium acetate (CH$_3$COOK is a salt of strong base and weak acid. it's aqueous solution will be basic and pH value will be >7 ≈ 8.8

$\sf CH_3COOK + H_2O \longrightarrow CH_3COOH + KOH$

$\Large \star$ Sodium carbonate is a salt of strong base and weak acid , Its aqueous solution is also basic and its pH value will be more than 10

$\sf Na_2CO_3 + H_2O \longrightarrow 2NaOH + H_2CO_3$

Thus, option (2) Na$_2$CO$_3$ has highest pH .