What you are looking for is SERP (search engine ranking position), not page rank.
Just go to the Google search engine main page and type in your keyword (key phrase) and look at the SERP results Google returns.
Then look through the pages of results to see if your Hub is listed.
Do it with and again without surrounding your keyword in quotes.
See if your Hub is there someplace or not. It's as simple as that.
BTW, in preferences in Google you can select to show 100 results per page instead of just 10.
Note that Google will show your page/Hub (if it shows it at all) in different SERP positions depending on the keyword.
If your Hub is about midget thongs, you might be number 50 for "midget thongs", but you might be number one for "red mesh midget thongs" (as long as "red mesh midget thongs" is in your Hub text).
Note that this has noting to do with PR-, PR0, PR1, PR2, PR3 ... PR10. Google assigns a PR rank to every page (not sites as a whole) and that has nothing to do with keywords, but how "valuable" your page is, in general.