For shortcut you can press Alt sight together Click on the equation button on the far right. Often the length is limited to between 200 and 400 words. You can type in the Formula box select a number format from the Number Format list and paste in functions and bookmarks using the Paste Function and Paste Bookmark lists.
Simply click From File and choose any Chemical Markup Language cml formatted file to insert the chemical formula.
You got some nice equilibrium arrows. This will bring up the Formula dialog with a default of SUM LEFT. Insert symbols by typing symbolname and press the space bar. Shortcut for typing chemical equation reaction in word.