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.
