Question

2. The largest number of molecules is present in (A) 54 g of nitrogen tetroxide (B) 28 g of carbon dioxide (C) 36 g of water (D) 46 g of ethyl alcohol .​with proper explanation.

Answer 1

Explanation:

As we can see that, water has the highest value for the number of moles in respect to other compounds. So, the largest number of molecules are present in water

Answer 2

Answer:

• (c) 36 g of water (a) 54 g of N2O5

Explanation:

N2O5 = Molecular mass = 28 + 80 = 108

108 g of N2O5 contains 6.023 x 1023 molecules.

• ∴ 54 g of N2O5 will contain ((6.023 x 1023)/108) x 54 = 3.0115 x 10 molecules.

(b) 28 g of CO2 CO2 = Molecular mass = 12 + 32 = 44 44 g of CO2 contains 6.023 x 1023 molecules.

• ∴ 28 g of CO2 will contain ((6.023 x 1023)/44) x 28 = 3.832 x 1023 molecules.

(c) 36 g of H2O H2O = Molecular mass = 2 + 16 = 18 18 g of H O contains 6.023 x 1023 molecules.

• ∴ 36 g of H2O will contain (6.023 x 1023) x 36 = 12.046 X 1023 molecules.

(d) 46 g of C2 H5 OH C2H5OH = Molecular mass = 24 + 6 + 16 = 46 46 g of C2H5OH contains 6.023 x 1023 molecules.

• So, among the 4, 36 g of water contain the largest number of molecules as 12.046 x 1023 .