Question

Calculate the number of moles in the following

(Atomic mass of Fe = 56u, S = 32u, O = 16u)



(a) 98 g of Fe

(b) 18.066 × 1021 atoms of SO2

(c) 12.044 × 1023 atoms of H2O​

Answer 1

Answer:

a) 98g of Fe

Atomic mass of Fe = 56 u

(M) Molar mass of Fe = 56g

No of moles (n)= W/M

=98g/56g moles

(n)= 1.75 moles

(b) 18.066×10power of 21 no of SO2 atoms

Moles(n) = given number of particles/NA

NA means number of particles

1NA= 6.022×10power of 23 = 1 moles

(n)= 18.006×10power of 21/ 6.022× 10power of23

(n)= 3 moles of SO2 are present

(c) 12.004×10power of 23 no.of H2O atoms

Moles(n)= given number of particles/NA

1NA= 6.022× 10power of 23 =1 moles

(n)= 12.004×10power of 23 /6.022×10power of 23

(n) = 2 moles of H2O are particles