which of the following contains highest number of molecules (a) 17.75cl2 (b) 8gCo (c) 4gHe (d) 28g Fe
Answers
Answer:
1 mole of any substance contains 6.02×10
23
(Avogadro's number ) of molecules.
A. 0.2 mole of H
2
contains 0.2×6.02×10
23
=1.2×10
23
molecules.
B. 8.0 mole of H
2
contains 8.0×6.02×10
23
=4.8×10
24
molecules.
C. 17 g of H
2
O =
18 g/mol
17 g
= 0.94 moles
17 g of H
2
O contains 0.94×6.02×10
23
=5.7×10
23
molecules.
D. 6.0 g of CO
2
=
44 g/mol
6.0 g
= 0.136 moles
6.0 g of CO
2
contains 0.136×6.02×10
23
=8.2×10
22
molecules.
Hence, 8.0 mole of H
2
contains the largest number of molecules
Explanation:
For a molecule,
molecular weight in grams = Avogadro's number(N
A
)=6.023×10
23
(A) 1g CO
2
44 gram of CO
2
=N
A
molecules
∴ 1 gram of CO
2
contains
44
1
×N
A
molecules
(B) 1g N
2
28 gram of N
2
=N
A
molecules
∴1 gram of N
2
contains
28
1
×N
A
molecules
(C) 1g H
2
2 gram of H
2
contains N
A
molecules
∴ 1 gram of H
2
contains
2
1
×N
A
molecules
(D) 1g CH
4
16 gram of CH
4
=N
A
molecules
∴ 1 gram of CH
4
=N
A
/16
Maximum number of molecules are found in 1 gram hydrogen.