Calculate Mass of Au Produced from 0.0500 mol Au2S3

[Quincy]

Homework Statement

What mass of Au is produced when 0.0500 mol of Au₂S₃ is reduced completely with excess H₂?

Homework Equations

The Attempt at a Solution

.100 mol Au³⁺ x 197/1 = 19.7 g

19.7 g is apparently wrong though according to the book; what am I doing wrong?

 

[Borek]

Look for a new book, 19.7g is the correct answer.