Question

If sulphur exists as S8 molecules calculate the no.of moles in 100g of sulphur

Answer 1

Given mass = 100 grams

Molar mass = 8 x 32 = 256 Grams

No: of moles = Given mass / Molar mass

= 100 / 256

= 0.3906 moles ( approx.)

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Q2.

No: of moles = 1.5 moles

Molar mass = 2 x 23 + 32 + 3 x 16

= 126 grams

No: of moles = Given mass / Molar mass

Mass = Molar mass x No: of moles

= 126 x 1.5

= 189 grams

Answer 2

1 molecule if S8 = 256a.m.u

= {256 × 1.6 × (10)to the power-24}grams

no. of moles = given mass / molar mass

given mass = 100gm