Question

The chief source of iodine, in which it is present as sodium iodate, is
A. Carnallie
B. Sea weeds
C. Caliche
D. Iodine never exists as sodium iodate.

Answer 1

Hint: Iodine can be obtained from the compounds or ores which contain iodine as its constituent element. From the above examples only caliche is a compound of sodium iodate so iodine is obtained from caliche.

Complete step by step solution:
Carnallite is an ore of magnesium and potassium. It contains chlorine atoms. After the crystallisation of potassium chloride from carnallite the liquid remains is called mother liquor. It contains bromine in the form of magnesium bromide and potassium bromide. The bromine can be easily obtained from the salt of magnesium bromide and potassium bromide.

Seaweeds are the plants present under the sea. Sea weeds do not contain sodium iodate.
Caliche is a hard rock that contains calcium carbonate with sand, rocks etc. Caliche contains sodium iodate. Thus iodine can be obtained from caliche.
Iodine exists as sodium iodate in caliche.
Thus the chief source of iodine, in which it is present as sodium iodate, is caliche.
Thus the correct option is C.

Note: Seaweeds are also a chief source of iodine. Iodine is easily obtained from sea weeds but it does not contain iodine as sodium iodate.