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Mole, molar mass, Avogadro number and molar volume
JEE Main level
Single correct option
Difficulty 2 of 3
mc124
An iron ore sample of mass 50 g contains 80% by mass
Fe
X
2
O
X
3
(rest has no iron). The mass of iron in the sample is (
Fe
=
56
,
O
=
16
)
A
40
g
B
35.00
g
C
14
g
D
28
g
Answer: D
Fe
X
2
O
X
3
present = 0.80 x 50 = 40 g. Fraction of Fe in
Fe
X
2
O
X
3
= 112/160 = 0.70. Mass of Fe = 40 x 0.70 = 28 g.
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