If I have your model information correctly you have a GVWR of 14,500 & GCWR of 19,500 which supports your 5,000 hitch. This is based on the 2010 model line so verify these numbers with your own documentation. So far, so good.
From what I have read , it looks like the curb weight of the PT Cruiser is somewhere around 3200#. Make sure you get it weighed including full fuel and any goodies it might be used to carry when being towed.
Now, go get your new RV weighed too. Have it loaded in a manner you think it will be when you hit the road. Full fuel, water, passengers, pets and such. I'm not as familiar with Class Bs but you may need to consider front and rear axle weights in the process. You may also have tire pressure guidelines to follow based on weight. Then again, maybe not. LOL Just do your homework and consider these items.
Your PT Cruiser is within your towing capabilities but don't forget a braking system to go with it. If you do, well...
ENJOY!