Which of the following has larger number of molecules?
7g of nitrogen or 1g of hydrogen
Answers
a. 7g of Nitrogen
Step - (1) : Calculate the number of moles of the given substance.
Number of moles of a substance is calculated by ,
Given weight of Nitrogen = 7g
Atomic weight of Nitrogen = 28 amu
Step-(2) : Multiplying the number of moles of the given substance with the Avogadro number.
Avogadro number = 6.023 × 10²³
Number of moles = 0.25 mol
Number of molecules in 7g of Nitrogen is 1.505 × 10²³.
b. 1g of Hydrogen
Step - (1) : Calculate the number of moles of the given substance.
Given weight of Hydrogen = 1
Atomic weight of hydrogen = 2 amu
Step-(2) : Multiplying the number of moles of the given substance with the Avogadro number.
Avogadro number = 6.023 × 10²³
Number of moles = 0.5 mol
Comparing the number of molecules in 7 grams of Nitrogen and in 1g of Hydrogen .
3.0115 × 10²³ > 1.505 × 10²³
Hence , 1g of Hydrogen contains more molecules than 7g of Nitrogen.
a. 7g of Nitrogen
Step - (1) : Calculate the number of moles of the given substance.
Number of moles of a substance is calculated by ,
n= Atomicweight/Givenweight
Given weight of Nitrogen = 7g
Atomic weight of Nitrogen = 28 amu
:⟹n (moles)
=28/7
:⟹n (moles)
= 4/1
:⟹ n _(moles)
=0.25mol
Step-(2) : Multiplying the number of moles of the given substance with the Avogadro number.
Avogadro number = 6.023 × 10²³
Number of moles = 0.25 mol
:⟹n (molecules)
=6.023×10 ⅔×0.25
:⟹ n (molecules)
=1.505×10 ⅔ ★
Number of molecules in 7g of Nitrogen is 1.505 × 10²³.
b. 1g of Hydrogen
Step - (1) : Calculate the number of moles of the given substance.
Given weight of Hydrogen = 1
Atomic weight of hydrogen = 2 amu
:⟹n (moles)
= 2/1
:⟹ n (moles) =0.5mol
Step-(2) : Multiplying the number of moles of the given substance with the Avogadro number.
Avogadro number = 6.023 × 10²³
Number of moles = 0.5 mol
:⟹n (molecules)
=6.023×10 ⅔ ×0.5
:⟹ n (molecules)
=3.0115×10 ⅔ ★
Comparing the number of molecules in 7 grams of Nitrogen and in 1g of Hydrogen .
⟶ 3.0115 × 10²³ > 1.505 × 10²³
⟶n (moleculesinH)
>n (moleculesinN)
Hence , 1g of Hydrogen contains more molecules than 7g of Nitrogen.