Question

Identify the inorganic impurity
A. Urine
B. Human faeces
C. Phosphates
D. Pesticides

Answer 1

Hint: The definition of organic molecules is the presence of carbon and hydrogen bonded together in it. Inorganic molecules on the other hand do not have carbon to hydrogen bonds. But carbon and hydrogen may be present in inorganic molecules as well but they will not be bonded to each other.

Complete answer: Let’s talk about the options given in the question one by one and see which of the molecules contain carbon to hydrogen bond that makes it an organic molecule and which does not contain the carbon-hydrogen bond.
Urine: Urine is the waste excreted out from the kidney. Urine is a mixture of both organic and inorganic waste materials. The major component of urine is urea (excluding water). Urea is an organic compound.
Human faeces: Again, human faeces is a mixture of both inorganic and organic wastes. Organic wastes make up to 84-93% of the solid wastes.
Phosphates: Phosphates are the form of phosphate that is present in nature. The molecular formula of the phosphate is $(PO_{4})^{3-}$. Since phosphate does not contain carbon hydrogen bond, hence it is an inorganic molecule.
Pesticides: The vast majority of the pesticides that were used in the past were inorganic molecules with lime, sulphur etc., but the modern pesticides are all made up of organic chemicals.
So, the correct answer is “Option C”.

Note:
Organic phosphates are the organic compounds with phosphates attached to it. The phosphate attaches itself to the carbon atom through one of its oxygen atoms.
Organic is a trending term today that refers to anything that is cultivated without the help of a chemical fertilizer, pesticides etc. It is also referred to as organic farming.