Question

Classify each of the following substances as either a strong or weak acid, strong or weak base, or a soluble or insoluble salt.
1. HClO4
2. PbCl2
3. KOH
4. HNO2
5. NaBr
a. strong acid
b. weak acid
c. strong base
d. weak base
e. soluble salt
f. insoluble salt

Answer 1

Answer:

KOH is a strong base, $HClO_{4}$ is a strong acid, $HNO_{2}$ is a weak acid, NaBr is a soluble salt and $PbCl_{2}$ is an insoluble salt

Explanation:

According to solubility rule, all chlorides, bromides and iodides of metal ions are soluble except for $Pb^{2+},Ag^{+}$ and Hg^{+}[/tex].

Therefore NaBr is a soluble salt and $PbCl_{2}$ is an insoluble salt.

There are seven strong acids : HCl, HBr, HI, $H_{2}SO_{4}$, $HNO_{3}$, $HClO_{3}$ and $HClO_{4}$.

All group IA metal hydroxides e.g. NaOH, KOH etc. are strong base. Also, $Ca(OH)_{2}$, $Sr(OH)_{2}$ and $Ba(OH)_{2}$ are strong bases.

So, KOH is a strong base, $HClO_{4}$ is a strong acid and $HNO_{2}$ is a weak acid.