Answer:
Explanation:
Percent composition is percentage by the mass of element present in the compound.
Given , Mass of sulfur= 32.1 amu
Mass of oxygen = 16.0 amu
Mass of sulfur trioxide 
= 32.1 amu + 3*16.0 amu = 80.1 amu
Answer:
We expect the enthalpies of combustion of two isomers to be different.
The molecular formular of the two molecules are very similar.
So the balanced chemical equation for the two combustion reactions are the same.
Explanation:
In calculation of the combustion enthalpiesfrom the isomers of the products and reactant.
The difference will be in the standard enthalpies of formation of the two combustion products.
The rod-shaped n- octane has vibrational and rotational motion possible more than the almost spherical neoprene.
Please note that since magnesium is in group 2 it has a valency of 2+ and so the formula for magnesium hydroxide is
M
g
(
O
H
)
2
[Mistake in question]
This is a typical neutralization reaction of an acid with a base to form a salt and water. The reaction is exothermic, gives off heat,
Δ
H
<
0
, and may be balanced by adding balancing numbers in front, ie adding molecules, in order to ensure that the total number of atoms of each element is the same on the left and right hand sides of the equation.
Doing so we obtain :
2
H
3
P
O
4
+
3
M
g
(
O
H
)
2
→
M
g
3
(
P
O
4
)
2
+
6
H
2
O
