Density is the ratio of mass to the volume.
The mathematical expression is given as:

Now, density of isooctane = 
Volume = 
Since, 1 gallon = 3.78 L
So, 3.8 gal = 
= 
As, 1 L = 1000 mL
Therefore,
= 
Volume in mL = 
Put the values,


= 
Hence, mass of 3.8 gal of the gasoline is
.
Non-polar covalent
Explanation:
Propane is made up of non-polar covalent bonds and it can be expected to dissolve in hexane and to not dissolve in water.
Propane is an hydrocarbon gas.
It forms by sharing of electrons between two atoms with very low electronegativity differences.
This differences results in equal sharing of the shared electron. Therefore they form a non-polar covalent bond.
Water is a polar covalent compound and cannot dissolve compounds that are not polar like propane.
Propane will only dissolve in a like substance like hexane which is equally non-polar.
learn more:
Covalent compounds brainly.com/question/3109255
#learnwithBrainly
It actually depends on the percentage of the concentration give. Percentages can be expressed as %mass/mass, %volume/volume or %mass/volume. To keep things simple, let's just assume that it is in %volume/volume. Thus, 13% of 520 mL is pure acid.
Volume of pure acid = 520*0.13 = 67.6 mL
The formula for mole is
n= Mass/Mol mass
Mol Mass: S=32
O2= 16(2)
—————
64 g/mol
N= 17.50 g
————— (cancel both g)
64 g/mol
= 0.27 mol is the answer