Equilibrium Quiz-7

What is $[H^+]$ of a solution that is 0.1 M HCN and 0.2 M NaCN?($K_a$ for $HCN = 6.2 \times10^{-10}$)

The pH of a buffer containing equal molar concentrations of a weak base and its chloride ($K_b$ for weak base $= 2 \times 10^{-5} ,$ log 2 = 0.3) is

Solution of 0.1 N $NH_4OH$ and 0.1 N $NH_4Cl$ has pH 9.25. Then $pK_b$ of $NH_4OH$ is

The most important buffer in the blood consists of :

The pH of blood is maintained by the balance between $H_2CO_3$ and $NaHCO_3$. If the amount of $CO_2$ in the blood is increased, how will it effect the pH of blood

If equal volumes of $BaCl_2$ and NaF solutions are mixed, which of these combinations will not give a precipitate? $K_{sp}$ of $BaF_2 = 1.7 \times10^{-7}$

The solubility products of $Al(OH)_3$ and $Zn(OH)_2$ are $8.5 \times 10^{-23}$and $1.8 \times 10^{-14}$, respectively. If $NH_4OH$ is added to a solution containing $Al^{+3}$ and $Zn^{+2}$ ions, then substance precipitated first is :

$Ca_3(PO_4)_2$ is insoluble in water. On adding a few drops of HCl to solid $Ca_3(PO_4)_2$ in contact with water, the solid dissolves. What is the reason?

Why does only $As^{3+}$get precipitated as $As_2S_3$ and not $Zn^{2+}$as ZnS when $H_2S$ is passed through an acidic solution containing $As^{3+}$ and $Zn^{2+}$?

When HCl (s) is passed through a saturated solution of common salt, pure NaCl is precipitated because :