About my major in the master's course.?

[TheDude]

I think it will be difficult to switch over to CS if you decided to, but certainly not impossible. Computer Science is not always about coding (depending on what career you choose), but math skills are extremely important. Chemistry uses a lot of math too, so you may do well in CS math-wise. With a CS degree, you have many career options such as:
Software Engineer
Systems Engineer
Software Developer
Java Developer
Business Analyst
.NET Developer
Web Developer
Systems Administrator
Project Manager
Network Engineer

If you're interested in business, you could work your way up and become a business analyst, etc. You could create websites for businesses, or you could work with new technologies such as the Oculus Rift.

If you decide to stay with your chemistry degree, here are some careers you can choose: http://www.westga.edu/~chem/chemcareers.htm

A lot of the careers stated on that page take many more years and a Ph.D. You can easily get a job with a CS degree, even without a Ph.D, but you will be wanted for higher positions with a Ph.D.

I hope I helped! Your English is great, by the way.