Weight has to do with how hard gravity is pulling on it. While mass is do to with the atoms in the matter.
Remember pH=-log(H ions). So it would be pH=-log(10^-7).
The total mass is the sum of mass of KCl and mass of
water:
total mass = 38 g + 225 g
total mass = 263 g
Therefore the mass percent of KCl is:
% KCl = (38 g / 263 g) * 100%
<span>% KCl = 14.45%</span>
Answer:
-2024 kJ
Explanation:
The combustion of propane is
C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(g)
And, ΔG° = ΔH° - TΔS°
Where T is the temperature in K.
ΔH° = ∑n*H°f, reactants - ∑n*H°f, products
Where n is the number of moles in the stoichiometry reaction. H°f, O₂(g) = 0 because it's a substance formed by only one element.
ΔH° = [4*(-226) +3*(-398)] - [-100] = -1998 kJ
ΔS° = ∑n*S°, reactants - ∑n*S°, products
ΔS° = [4*(184) + 3*214] - [5*204 + 271] = 87 J/K = 0.087 kJ/K
So
ΔG° = -1998 - 298*0.087
ΔG° = -2024 kJ
