1. I played football yesterday. --> I have played football recently. --> I was playing football yesterday all day long. 2. I worked with my mother at home yesterday. --> I have already worked with my mum. --> I was working with my mom yesterday. 3. I went to the cinema last week. --> I have gone to the cinema recently. --> While I was going to the cinema, my friend broke his leg. 4. I didn't do my homework. --> I haven't done my homework yet. --> I wasn't doing my homework all day long. 5. I made an apple pie one month ago. --> I have already made an apple pie. --> I was making an apple pie when you came home.
СnH2n + Br2 = CnH2nBr2
масса 1 моль алкена = 1 моль/0,02 моль*1,4 г = 70 г
14n = 70
n = 5
формула С5Н10