The outlets are 110V 60 Hz AC as in Canada. Battery rechargers are typically 110-220V AC 50/60 Hz which means they work anywhere in the world anyway.
The plugs are the same in the DR as Canada, although at times you will find the Euro design - two round holes vs. two slots like in Canada. Mostly where Italians built the hotel from materials sourced there. The adapter is about 89 cents at any dollar store in a reasonably ethnic neighbourhood.
The razor uses a motor which might matter if it was not 120V/60 AC in the DR, but it is so you are fine. (some motors use the frequency to control speed).
Note if you look at the label on your battery charger (or an adapter for a PC, or video camera, etc.) it will say what voltage it uses:
Stated typically as a voltage ( 120 V AC or 220 V AC) and a frequency (50 hz or 60 Hz). Have a look and it will probably say 110-250V 50/60 Hz AC which is basically the entire world, and also Mars.
