A compound containing elements A and B is decomposed to give 0.177 mol A and 0.354 mol B. What is the compound's empirical formula?

Question

a. AB

b. A2B

c. AB₂

d. A₂B₃

Answer 1

Hi Anna! For an empirical formula, we're essentially looking for a ratio between the two elements given. If we set up our moles as a ratio with A on bottom, (0.354 mol/0.177 mol), our ratio simplifies to 2/1, meaning we have 2 Bs for every 1 A, giving us answer choice c, AB₂. Hope this helps!