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Mole, molar mass, Avogadro number and molar volume
JEE Main level
Numerical answer
Difficulty 2 of 3
mc126
How many electrons are present in 3.6 g of water (
H
X
2
O
,
M
=
18
)? Take
N
A
=
6.02
×
1
0
23
mo
l
−
1
. Give the answer in units of
1
0
23
, to two decimal places.
Numerical answer type, answer in x10^23, tolerance 0.02.
Answer: 12.04 x10^23
Moles of water
=
3.6/18
=
0.20
. Each
H
X
2
O
molecule has
2
(
1
)
+
8
=
10
electrons. Electrons
=
0.20
×
10
×
6.02
×
1
0
23
=
12.04
×
1
0
23
.
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