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
Hydrogen is grouped with the alkali metals because they are grouped based on their properties and behavior, and like the other elements in Group 1 (1A), it only has one valence.
1. Iron fillings are magnetic, so use a magnet to pull the iron fillings out of the mix.
2. Then you can put the salt and sand mixture into water, since salt is soluble, and the salt will dissolve, leaving you with sand.
The bond between the 2 Cl atoms in a Cl₂ molecule is a covalent bond.
to break this covalent bond, energy is required.
when new bonds form, energy is released as the bond formation makes the molecule stable. molecules with low energy levels are usually stable.
To break the covalent bond, energy is required in other words energy is absorbed.
therefore to break the covalent bond in Cl₂ molecule
1)energy is absorbed
It took 380,000 years for electrons to be trapped in orbits around nuclei, forming the first atoms.
These were mainly helium and hydrogen, which are still by far the most abundant elements in the universe. Present observations suggest that the first stars formed from clouds of gas around 150–200 million years after the Big Bang. Heavier atoms such as carbon, oxygen and iron, have since been continuously produced in the hearts of stars and catapulted throughout the universe in spectacular stellar explosions called supernovae.
