Answer:
31 ml
Explanation:
At constant temperature of 30°C;
Using Boyles Law:

775 × 30 = 750V2
V2 = (775 × 30) / 750 = 31ml
Because molecules in the air scatter blue light from<span> the sun </span>more than<span> they </span>scatter red light<span>.</span>

Actually Welcome to the concept of General organic chemistry.
1.) The formula for alkanes is Cn H2n+2
===> here n = 500, hence we get as,
C500, 2n+2 = 2(500)+2 ==> 1000+2 ==> 1002
hence the formula is ==> C500 H1002
2.) The formula for alkenes is,
CnH2n
hence, here n = 15
so we get as,
===> C15 H30
1- physical
2-chemical
3-Physical
4-Chemical
5-I’m not sure
I haven’t done this in a while so these may be wrong sorry