Answer:
half-life of 5,700 ± 40 years
Explanation:
Coal will eventually run out as it is an non-renewable energy. these are when they cannot be reproduced to make more,unlike would as u can replant them to create trees
Answer : The internal energy change is, -506.3 kJ/mol
Explanation :
Formula used :
or,
where,
= change in enthalpy = 
= change in internal energy = ?
= change in moles
Change in moles = Number of moles of product side - Number of moles of reactant side
According to the reaction:
Change in moles = 0 - 2 = -2 mole
That means, value of 
= 0
R = gas constant = 8.314 J/mol.K
T = temperature = 
Now put all the given values in the above formula, we get
Therefore, the internal energy change is -506.3 kJ/mol
Answer:
D no. is the answer of your question
<h3>
Answer:</h3>
Balanced equation: 4Fe + 3O₂ → 2Fe₂O₃
Moles of oxygen gas = 9 moles
<h3>
Explanation:</h3>
To answer the question;
- We first write the balanced equation between iron metal and Oxygen
- The balanced equation is given as;
4Fe + 3O₂ → 2Fe₂O₃
- We are given 6 moles of Fe₂O₃
We are required to determine the number of moles of oxygen needed to form 6 moles of Fe₂O₃.
- From the equation, 3 moles of oxygen gas reacts to produce 2 moles of Fe₂O₃
- This means, the mole ratio of O₂ to Fe₂O₃ is 3 : 2
Therefore; Moles of O₂ = Moles of Fe₂O₃ × 3/2
Hence, moles of oxygen = 6 moles × 3/2
= 9 moles
Thus, Moles of Oxygen needed is 9 moles
