Cyclic voltammetry for irreversible reactions

I’m new to electrochemistry and I was wondering two things, sorry if these two problems are trivial but I just can’t find anything close to this in the literature.

First, the following reaction is irreversible, right? an intermediate Q is formed:
$B + e^{-} rightarrow Q$

and another reaction follows where it is converted to a different product X:

$Q rightarrow X$.

Then I’m supposed to sketch a cyclic voltammogram (CV) of this process, but I was taught that for irreversible processes a CV is not useful.

I looked pretty much all day for a similar reaction and the closest I could find is in "A Practical Beginner’s Guide to Cyclic Voltammetry" where the following reactions are presented:

$text{Ox} + e^{-} rightleftharpoons text{Red}$

$text{Red} rightarrow Z$

These are defined as EC coupled reaction: reversible electron transfer Er following by an irreversible homogeneous chemical reaction Ci.

The ones I am given are not the same, I think. But I have no idea how to sketch a CV for that process. Am I interpreting the given reactions wrongly?