Question

The compound called microcosmic salt is:

• A. $N{a}_{2}HP{O}_4.2H_{2}O$
• B. $Na\left(N{H}_4\right)HP{O}_4.4H_{2}O$
• C. $N{a}_{2}N{H}_{4}P{O}_4.2H_{2}O$
• D. $(N{H}_4{)}_{2}HP{O}_4.2H_{2}O$

Answer 1

Answer: (B)

$Na\left(N{H}_4\right)HP{O}_4.4H_{2}O$

Microcosmic salt is a salt found in urine with the formula $Na\left(N{H}_4\right)HP{O}_4$. It is left behind in the residues after extracting the urea from dried urine crystals with alcohol. In the mineral form, microcosmic salt is called stercorite .

The first extraction of pure phosphorus came from this salt, when Henning Brandt attempted to extract gold from urine.

Microcosmic salt is used in the laboratory as an essential ingredient of the microcosmic salt bead test for identification of metallic radicals on the basis of the color they produce in oxidising or reducing flame, in hot or cold condition.

Hence the correct option is 'B'