Question

Calculate the number of molecules in 3.4 gm of h2s

Answer 1

Molecular weight of H2S= 2(1)+32= 34grams
34g= 1 mole = 6.022*10^23 molecules
3.4g=6.022*10^23/10= 6.022*10^22 molecules

HOPE THIS HELPS :)

Answer 2

molecular mass of H2S is 34 g/mol

no. of moles = given mass / molecular mass

= 3.4÷34

= 0.1 moles

1 mole contains 6.022 *10^23 molecules

then, 0.1 moles contains

= 6.022*10^23 * 0.1

= 6.022 *10^22 molecules