Question

which is the following has the highest number of moles
a. 98 g of H2so4
b. 80 g of NaOH
c. 26g of He
d. 51 g of NH3​

Answer 1

we have to check, which of the following has the highest number of moles ?

a. 98g of H₂SO₄

b. 80g of NaOH

c. 26g of He

d 51g of NH₃

solution : we know,

• number of moles of compound = given weight/molecular weight
• number of moles of element = given weight/atomic weight

let's find no of moles of all given substances.

a. given weight = 98g

molecular weight of H₂SO₄ = 98 g/mol

so, no of moles of H₂SO₄ = 98/98 = 1

b. given weight = 80g

molecular weight of NaOH = 40g/mol

so, no of moles of NaOH = 80/40 = 2

c. given weight = 26g

atomic weight of He = 4g/mol

so, no of moles of He = 26/4 = 6.5

d. given weight= 51g

molecular weight of NH₃ = 17 g/mol

so, no of moles of NH₃ = 51/17 = 3

Therefore option (c) 26g of He, has the highest number of moles.