Neet Solved Paper 2015 Question 4

Question: Metals are usually not found as nitrates in their ores. Out of the following two (a and b) reasons which is/are true for the above observation?

I. Metal nitrates are highly unstable. II. Metal nitrates are highly soluble in water.

Options:

A) I and II are true

B) I and II are false

C) I is false but II is true

D) I is true but II is false

Show Answer

Answer:

Correct Answer: D

Solution:

  • Metals are usually not found as nitrates in their ores, because metal nitrates are highly, soluble in water. For example, $ KNO _3 $ (salt peter) would be classified as completely soluble. Thus, $ KNO _3 $ could be expected to dissociate completely in aqueous solution into $ {K^{+}} $ and $ NO_3^{-} $ ions $ KNO _3{K^{+}}(aq)+NO_3^{-}(aq) $ The nitrate anion has three equivalent oxygen surrounding a central nitrogen atom. This tends to spread the single negative charge and make it easier for water (using hydrogen bonds) to separate the ions in solution.