First, about the email:
Do you have a deadline coming up, for applying for a master’s? If so, then you should probably send him a polite reminder, something along the lines of:
Dear Dr. X, I was wondering if you had given any more consideration to the projects you'd mentioned earlier.
Do not say something like “my future depends on this.” Firstly, your future does not. If this particular master’s opportunity doesn’t work out, it is by no means the end of your career. Secondly, it will come across as rude: The Professor is aware that master’s applications are important to your career.
Don’t expect professors to respond terribly soon. They receive a large amount of email, and are often extremely busy balancing research, administration, supervising, and teaching. If you have an impending deadline, or it has been long enough that you believe you have been forgotten, you can send a polite reminder. But pestering will only annoy the professor.
Secondly, about the projects:
Is he asking you to do projects for him, unpaid, before you have been accepted as a master’s student? This is highly unconventional, and seems like it might possibly be a scam, to get you to work on projects without paying you or giving you credit towards an academic degree.
What country is this master’s in? Usually, professors do not directly choose who is admitted to a master’s program. So your professor may not be able to guarantee your admission, even if you do good work for them on this project.
In any case, it’s not normal to be given months of homework to “prove yourself” before starting a master’s. Usually your bachelor’s grades and projects, along with reference letters, are what you are judged on.
So I would be very wary of this situation, unless I am misunderstanding what is actually happening.