Question

Give the chemical properties of sulphuric acid with complete reaction.

Answer 1

Chemical properties of ${\mathrm{H}}_2{\mathrm{SO}}_4$ (Sulphuric acid)

1. ${\mathrm{H}}_2{\mathrm{SO}}_4$ is a strong and dibasic acid that can provide two positively charged hydrogen ions or protons when reacting with a base.

2. ${\mathrm{H}}_2{\mathrm{SO}}_4$ undergoes primary dissociation and secondary dissociation when react with water as shown

Primary dissociation $\to$ $$\begin{gathered} {\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{l}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{H}}_3{\mathrm{O}}^{+}\left(\mathrm{aq}\right)+{\mathrm{HSO}}_4^{-}\left(\mathrm{aq}\right) \\ \mathrm{Sulphuric}\mathrm{Water}\mathrm{Hydronium}\mathrm{Hydrogen} \\ \mathrm{acid}\mathrm{ion}\mathrm{sulphate}\mathrm{ion} \end{gathered}$$

Secondary dissociation $\to$$$\begin{gathered} {\mathrm{HSO}}_4^{-}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{H}}_3{\mathrm{O}}^{+}\left(\mathrm{aq}\right)+{\mathrm{SO}}_4^{-2}\left(\mathrm{aq}\right) \\ \mathrm{Hydrogen}\mathrm{Water}\mathrm{Hydronium}\mathrm{Sulphate} \\ \mathrm{sulphate}\mathrm{ion}\mathrm{ion}\mathrm{ion} \end{gathered}$$

3. Sulphuric acid reacts with base to give salts and water as a product.

For example: Sulphuric acid reacts with Sodium hydroxide to give Sodium sulphate and Water as a product.

$$\begin{gathered} {\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{l}\right)+2\mathrm{NaOH}\left(\mathrm{l}\right)\to {\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{s}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ \mathrm{Sulphuric}\mathrm{Sodium}\mathrm{Sodium}\mathrm{Water} \\ \mathrm{acid}\mathrm{hydroxide}\mathrm{sulphate} \end{gathered}$$

4. When active metals like Sodium, Zinc, Aluminium etc., react with dilute Sulphuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ then it liberates Hydrogen gas$\left({\mathrm{H}}_2\right)$.

For example: Zinc reacts with Sulphuric acid to give Zinc sulphate and Hydrogen gas as a products.

$$\begin{gathered} \mathrm{Zn}\left(\mathrm{s}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{l}\right)\to {\mathrm{ZnSO}}_4\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \mathrm{Zinc}\mathrm{Sulphuric}\mathrm{Zinc}\mathrm{Hydrogen} \\ \mathrm{acid}\mathrm{sulphate}\mathrm{gas} \end{gathered}$$

5. Sulphuric acid act as an dehydrating agent.

For example: Sulphuric acid removes water molecules from the blue crystal Copper sulphate and forms white colored Copper sulphate.

Reaction:

$$\begin{gathered} {\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}\left(\mathrm{s}\right)\stackrel{\mathrm{conc}.{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }{\mathrm{CuSO}}_4\left(\mathrm{s}\right)+5{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ \mathrm{Blue}\mathrm{colored}\mathrm{White}\mathrm{colored}\mathrm{Water} \\ \mathrm{Copper}\mathrm{sulphate}\mathrm{Copper}\mathrm{sulphate} \end{gathered}$$

6. Sulphuric acid decomposes metal carbonates and bicarbonates to liberate Carbon dioxide gas.

For example: Sodium carbonates reacts with Sulphuric acid to give Sodium sulphate, Water and Carbon dioxide gas as a products.

$$\begin{gathered} {\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{l}\right)\to {\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right) \\ \mathrm{Sodium}\mathrm{Sulphuric}\mathrm{Sodium}\mathrm{Water}\mathrm{Carbon}\mathrm{dioxide} \\ \mathrm{carbonate}\mathrm{acid}\mathrm{sulphate}\mathrm{gas} \end{gathered}$$

while Sodium bicarbonate reacts with Sulphuric acid to give Sodium sulphate, Water and Carbon dioxide gas as a products.

$$\begin{gathered} 2{\mathrm{NaHCO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{l}\right)\to {\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{s}\right)+2{\mathrm{H}}_2\mathrm{O}+2{\mathrm{CO}}_2\left(\mathrm{g}\right) \\ \mathrm{Sodium}\mathrm{Sulphuric}\mathrm{Sodium}\mathrm{Water}\mathrm{Carbon}\mathrm{dioxide} \\ \mathrm{bicarbonate}\mathrm{acid}\mathrm{sulphate}\mathrm{gas} \end{gathered}$$