Answer:
A sample of water boils and releases gas.
Explanation:
Physical change is a change where no any chemical reaction takes place only the chemical composition of matter changes. It is a reversible process .
Burning of newspaper, rusting of iron, plant changes carbon dioxide and water into sugar (photosynthesis) are chemical reaction and irreversible process.
Answer:
a. 7278 K
b. 4.542 × 10⁻³¹
Explanation:
a.
Let´s consider the following reaction.
N₂(g) + O₂(g) ⇄ 2 NO(g)
The reaction is spontaneous when:
ΔG° < 0 [1]
Let's consider a second relation:
ΔG° = ΔH° - T × ΔS° [2]
Combining [1] and [2],
ΔH° - T × ΔS° < 0
ΔH° < T × ΔS°
T > ΔH°/ΔS°
T > (180.5 × 10³ J/mol)/(24.80 J/mol.K)
T > 7278 K
b.
First, we will calculate ΔG° at 25°C + 273.15 = 298 K
ΔG° = ΔH° - T × ΔS°
ΔG° = 180.5 kJ/mol - 298 K × 24.80 × 10⁻³ kJ/mol.K
ΔG° = 173.1 kJ/mol
We can calculate the equilibrium constant using the following expression.
ΔG° = - R × T × lnK
lnK = - ΔG° / R × T
lnK = - 173.1 × 10³ J/mol / (8.314 J/mol.K) × 298 K
K = 4.542 × 10⁻³¹
2C4H10 + 13O2 → 8CO2 + 10H2O Since the equation is balanced, we can set up a proportion: 13 moles of O2 react with 2 moles of C4H10x moles of O2 react with 0.425 moles of C4H10 13 → 2x → 0.425 x = 13 * 0.425 / 2 = 2.7625 <span>2.7625 moles of O2 react with 0.425 moles of C4H10</span>
