Question

Rearrange the following (I to IV) in the order of increasin masses and choose the correct answer from (A), (B), (C) and (D)
(At. Mass N=14, O=16, Cu=63)
(I) 1 molecule of O
(II) 1 atom of nitrogen
(III) `1xx10^(-10)`g molecular mass of oxygen
(IV) `1xx10^(-7)` atomic mass of copper.
A. II lt I lt III lt IV
B. IV lt III lt II lt I
C. II lt III lt I lt IV
D. III lt IV lt I lt II

Answer 1

Correct Answer - A
(I) Mass of one O atom `= (16g)/(6.02xx10^(23))`
`=2.66xx10^(-23)g`
(II) Mass of one N atom `=(14g)/(6.02xx10^(23))`
`=2.33xx10^(-23)`g
(III) 1g-molecule of oxygen = 32 g
`1xx10^(10)` g-molecule of oxygen
`=32xx10^(-10)=3.2xx10^(-9)g`
(IV) 1 g-atom of copper = 63 g
`1xx10^(-7)g` g-atom of copper
`=63xx10^(-7)=6.3xx10^(-6)g`
Arranging in the increasing order of masses
II lt I lt III lt IV