Are there any free software for drawing experimental set-ups?

As a student, I would like to make images of experimental set-ups described in the textbooks. An example of such set-ups is attached. (The one in my textbooks is slightly different from the attached one, so I can't use this directly.) If I take pictures of those set-ups, the quality wouldn't be good. Unfortunately, the Internet pictures do not suffice.
I can't afford to buy such a software, so I'm looking for free ones if possible. Yet all experimental set-up drawing softwares I've found so far are either free trial or paid only.
There is little room for customization for Chemix. (I can't even add text!) I heard of Inkscape and Dia, but I don't see how they can assist me in drawing experimental set-ups. If I could find templates of experimental apparatus for them, I would use them.

To sum up, I would like to find a software that
1) is free (NOT trial or paid)
2) can be used to draw 2D experimental set-ups
3) has room for customization (e.g. adding texts)
4) preferably pre-loaded with some simplified drawing of experimental apparatus, or has templates of experimental apparatus that I can use
5) preferably working offline
6) is virus-free
I know, such software is difficult to find, but really, I don't want to resort to Paint x_x
Thanks.