Answer:
The answer to your question is ΔH rxn = - 849.5 kJ/mol
Explanation:
Reaction
2Al(s) + Fe₂O₃ (s) ⇒ 2Fe (s) + Al₂O₃ (s)
Enthalpy of reaction
ΔHrxn = ∑ H products - ∑ H reactants
ΔHrxn = ∑( H (Al₂O₃) + H (Fe) - ∑ ( H Fe₂O₃ + H Al)
ΔHrxn = [-1675 + 0] - [ -825.5 + 0]
ΔHrxn = -1675 + 825.5
ΔHrxn = - 849.5 kJ/mol
Answer:
t = 49.20 years
Explanation:
Half life expression for first order kinetic is:
Half life = 12.3 years
Where, k is rate constant
So,
The rate constant, k = 0.05635 years⁻¹
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given:
is 6.25 % of . So,
= 0.0625
t = ?
<u>t = 49.20 years</u>
Atoms of metals tend to 2. Lose electrons and form positive ions.
The heat absorbed by the metal is 729.9 kJ.
We can calculate the heat absorbed by the copper using the formula below
⇒ Formula:
Q = cm(t₂-t₁)............... Equation 1
⇒ where:
- Q = Heat absorbed by the copper
- c = Specific heat capacity of the copper
- m = Mass of the copper
- t₁ = Initial temperature
- t₂ = Final Temperature
From the question,
⇒Given:
- m = 6.22 kg
- c of copper = 385 J/kg.°C
- t₁ = 20.5°C
- t₂ = 325.3°C
⇒Substitute these values into equation 1
- Q = 6.22×385(325.3-20.5)
- Q = 6.22×385×304.8
- Q = 729904.56 J
- Q = 729.9 kJ
Hence the heat absorbed by the metal is 729.9 kJ
Learn more about heat energy here: brainly.com/question/13439286