Beyond scope( Master thesis) I'm master student and I'm working on my thesis that includes lab work. I was written my proposal last semester and I've done lot of research about instruments that I'm going to use according to the instruction that my supervisor gave it to me. Now he comping up with new experiments and instruments every day that he didn't mentioned. He expect me to make chemical solutions that I'm going to use but I didn't prepared myself for that and now I'm confused and stressful.Now I don't know if it is right to complain about this or I have to do that part anyway. I appreciate it if somebody can tell me what to do?!
First off, take a deep breadth and relax.

It's hard for Random Internet People (tm) to really know what's in scope and what's out of scope for your work. You should bring up your concerns with you adviser. He exists to advise, direct, and guide you. He's not the enemy. 

If you feel like the work your adviser is suggesting is too much or unrelated to your thesis, you should say so. He might not realize how much effort/time the experiments he's suggesting will take. Or maybe he knows some way to make then take up less effort.

If you're worried about talking to your adviser, you can try to approach a more senior student in his group or another professor. They probably know you, your adviser, and your work better than we do and can help suggest specif strategies to talk to you adviser about the situation and offer advice on how to accomplish your work.