Text Entry Box issue when user includes a blank space

Perhaps I did a poor job explaining.  The correct answer is "bromine trioxide", however, if a student types "bromine trioxide " (notice a space after trioxide) the answer is considered incorrect upon clicking on submit.  I discovered that i can add "bromine trioxide " with a blank space after the desired answer and the activity will work as intended, however, it seems like this would be a common issue when users are typing in text.  What if a user clicks on the space bar twice before submitting?  This would once again trigger an incorrect response.  It would be helpful if the program ignored user inserted blank spaces after typed text.  Hopefully this makes sense and thanks for looking at this.