<span>Enthalpy is a state function because its change depends only on initial and final conditions.</span>
Answer:
ΔG°rxn = -69.0 kJ
Explanation:
Let's consider the following thermochemical equation.
N₂O(g) + NO₂(g) → 3 NO(g) ΔG°rxn = -23.0 kJ
Since ΔG°rxn < 0, this reaction is exergonic, that is, 23.0 kJ of energy are released. The Gibbs free energy is an extensive property, meaning that it depends on the amount of matter. Then, if we multiply the amount of matter by 3 (by multiplying the stoichiometric coefficients by 3), the ΔG°rxn will also be tripled.
3 N₂O(g) + 3 NO₂(g) → 9 NO(g) ΔG°rxn = -69.0 kJ
sun light and chemical create photochemical smog
Answer:
The specific heat of the unknown substance is 1.22 J/g.°C.
Explanation:
Heat lost by substance (Qc) = Heat gained by the water (Qw)
,
<em>- (Qc) = (Qw).</em>
<em></em>
- We can calculate the amount of heat (Qw) gained by water using the relation:
Qw = m.c.ΔT,
where, Qw is the amount of heat released to water (Q = ??? J).
m is the mass of water (m = 110.0 g).
c is the specific heat capacity of solution (c = 4.18 J/g.°C).
ΔT is the difference in T (ΔT = final temperature - initial temperature = 32.4°C - 24.2°C = 8.2°C).
<em>∴ Q = m.c.ΔT = </em>(110.0 g)(4.18 J/g.°C)(8.2°C) = <em>3770.36 J.</em>
- Now, the amount of heat lost by the substance <em>(Qc) = - 3770.36 J.</em>
(Qc) = m.c.ΔT,
where, Qc is the amount of heat lost by substance (Qc = - 3770.36 J).
m is the mass of water (m = 42.5 g).
c is the specific heat capacity of solution (c = ??? J/g.°C).
ΔT is the difference in T (ΔT = final temperature - initial temperature = 32.4°C - 105.0°C = -72.6°C).
∴ (- 3770.36 J) = (42.5 g)(c)(-72.6°C).
∴ c = (- 3770.36 J)/(42.5 g)(-72.6°C) = 1.222 J/g.°C.