Saying that you will do something in the near future in CV and statement of purpose when applying for grad school.
In CVs, it's not unusual to write "planned" or "expected" next to certain lines on a CV that are not yet realized but where there is a very strong reason to expect the event will happen. Although I don't think there's a hard and fast rule about when you should or shouldn't do this, the most important thing is to be honest and unambiguously clear about what stage and state a particular piece of work is. If things fall through and something doesn't happen according to the plan, nobody who read your CV before should feel like you misled them.

The most common example of this is a listing of a degree with an expected or planned date that it will be awarded. This is common enough that I might even find it unusual surprising if a student in a degree program did not list a degree in this way. Because less of this is within an author's control, I'd be very hesitant to list dates next to any unpublished papers on my CV. 

That said, it's not uncommon to list papers or projects at different points along a process — especially for more junior scholars who don't have a lot on their CV otherwise. For example, it's normal to list papers as: in preparation (i.e., unfinished), under review (i.e., submitted but without a decision), in press (i.e., accepted but unpublished), etc. Again, managing expectations is key here. On my CV, I list working papers in a section that is entirely separate from my list of publications.

In terms of your personal statement, I think you absolutely should list papers in preparation and make it clear where and when you plan to submit them. Again, just explain things clearly in a way that will honestly communicate the state of your research.