For years I used to write my ‘heat under reflux’ in a text box and group it with an arrow. However, if you use an arrow from Insert>Equation you will have an annotated arrow which is treated as a Word symbol.
2. Type into the box ‘heat under reflux / H+’. The font will be italic so change that.
3. The + sign of H+ can’t be a superscript so raise it by 1.5 points:
4. You will now have this:
The font will be Cambria Math (sic) which can be changed using this macro.