Question

application of double displacement reaction in paint and pharmaceutical industry

Answer 1

Answer on Question #42228, Chemistry, Organic Chemistry

Question:

Dear Sir,

I have a question about what are the applications of double displacement reaction in paint & pharmaceutical industry?? 3 or 4 points?

Answer:

Applications of double displacement reactions in paint:

Zinc chrome yellow is an yellow pigment. It is formally basic zinc chromate, $\mathrm{ZnCrO_4\cdot Zn(OH)_2}$ . It can be obtained by mixing potassium chromate $\mathrm{K}_2\mathrm{CrO}_4$ and zinc chloride $\mathrm{ZnCl}_2$ solutions to produce Zinc chromate through a double displacement reaction and then adding NaOH to make the solution basic. The result is solid yellow $\mathrm{ZnCrO_4\cdot Zn(OH)_2}$ .

$$\begin{array}{l} \mathrm {N a} _ {2} \mathrm {C r O} _ {4} + \mathrm {Z n S O} _ {4} \rightarrow \mathrm {Z n C r O} _ {4} + \mathrm {N a} _ {2} \mathrm {S O} _ {4} \\ 2 \mathrm {Z n C r O} _ {4} + 2 \mathrm {N a O H} \rightarrow \mathrm {Z n C r O} _ {4} \cdot \mathrm {Z n} (\mathrm {O H}) _ {2} + \mathrm {N a} _ {2} \mathrm {C r O} _ {4} \\ \end{array}$$

A solution of slaked lime is used for white washing walls. Calcium hydroxide reacts slowly with the carbon dioxide in air to form a thin layer of calcium carbonate on the walls. Calcium carbonate is formed after two to three days of white washing and gives a shiny finish to the walls. The formation of calcium carbonate is an example of double displacement reaction.

$$\mathrm {C a} (\mathrm {O H}) _ {2} (\mathrm {a q}) + \mathrm {C O} _ {2} (\mathrm {g}) \rightarrow \mathrm {C a C O} _ {3} (\mathrm {s}) + \mathrm {H} _ {2} \mathrm {O} (\mathrm {l})$$

In this way, different colored pigments can be prepared by double displacement reactions.

Applications of double displacement reactions in pharmaceutical industry:

Aspirin, also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic. It is produced by acylation of salicilic acid by a double displacement reaction.

Diphenhydramine is a first-generation antihistamine possessing anticholinergic, antitussive, antiemetic, and sedative properties. Diphenhydramine can be synthesized by a double displacement reaction between bromodiphenylmethane and 2-dimethylaminoethanol:

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