Some Basic Concepts Of Chemistry Question 102
Question: Rearrange the following (I to IV) in the order of increasing masses and choose the correct answer from , , and (Atomic mass: N=14, O=16, Cu=63).
1 molecule of oxygen 1 atom of nitrogen $ 1\times {10^{-10}} $ g molecular weight of oxygen $ 1\times {10^{-10}} $ g atomic weight of copper
Options:
A) II<I<III<IV
B) IV<III<II<I
C) II<III<I<IV
D) III<IV<I<II
Show Answer
Answer:
Correct Answer: A
Solution:
[a] (I) 1 molecule of oxygen $ \because $ $ 6\times 10^{23} $ molecule has mass $ =32gm $
$ \therefore $ 1 molecule of $ O _2 $ has mass $ =\frac{32}{6\times 10^{23}} $
$ =5.3\times {10^{-23}}gm $
(II) 1 atom of nitrogen
$ \because $ $ 2\times 6\times 10^{23} $ atoms of $ N _2 $ has mass = 28gm
$ \therefore $ 1 atom of $ N _2 $ has mass $ =\frac{28}{2\times 6\times 10^{23}} $
$ =2.3\times {10^{-23}}gm $ (III) $ 1\times {10^{-10}}g $ molecular weight of oxygen g atomic weight $ =2\times 1\times {10^{-10}}=2\times {10^{-10}}g $ (IV) $ 1\times {10^{-10}}g $ atomic weight of copper So, order of increasing masses $ II<I<III<IV $ .
