Answer:
1.204×10^(23)
Step-by-step explanation:
Molecular weight of H2S, M = 1*2+32 = 34
weight of sample, m = 6.82 gram
now number of moles, n= m/M
n= 6.82/34 = 0.200 moles
1 mole has 6.023×10^(23) molecules of H2S.
therefore 0.2 moles of H2S will have 0.2×6.023×10^(23) = 1.204×10^(23) number of H2S molecules.