Question

Calculate the number of moles in 20 g of HNO³

Answer 1

✠Given to find the total no.of moles for 20g of HNO3

✠SOLUTION:-

We have formula to find the number of moles of a compound that is

✠No.of moles = Given mass/ Molecular weight of compound  

So,

Molecular weight of HNO3 =

It consists of Hydrogen(H) , Nitrogen(N) , Oxygen(O)

We know the atomic mass of the elements,  

✠Hydrogen = 1

✠Nitrogen = 14

✠Oxygen = 16

HNO3 = Hydrogen + Nitrogen + 3 moles of Oxygen

= 1+ 14 + 3(16)

= 15 + 48

=63 g

HNO3 = 63g

No.of moles = Given mass/ Molecular weight of compound  

= 20g/ 63g

= 20/63

= 0.317 moles

_________________

✠Know more :-

✠Some atomic mass of  first 20 elements

Hydrogen - 1

Helium - 4

Lithium - 7

Beryllium - 9

Boron - 11

Carbon - 12

Nitrogen - 14

Oxygen - 16

Fluorine - 19

Neon - 20

Sodium - 23

Magnesium - 24

Aluminum- 27

Silicon- 28

Phosphorus- 31

Sulphur - 32

Chlorine - 35.5

Argon - 40

Pottasium- 39

Calcium - 40