3-ethyl-5,6-dimethyloctane
3-ethyl-2,3-dimethylpentane
In this kind of exercises, you should use the "ideal gas" rules: PV = nRT
P should be in Pascal:
445mmHg = 59328Pa
1225mmHg = 163319Pa
V should be in cubic meter:
16L = 0.016 m3
R =

= constant

=

==> P1 * V1 = P2 * V2
V2 =

=
V2 = 0.00581 m3 = 5.81 L
The red is an oxygen molecule. 1 oxygen and 2 hydrogen =h2o or water!
varying composition is not a property of a pure substance