Answer: B) The fireworks give off heat
Answer:
76.03 °C.
Explanation:
Equation:
C2H5OH(l) --> C2H5OH(g)
ΔHvaporization = ΔH(products) - ΔH (reactants)
= (-235.1 kJ/mol) - (-277.7 kK/mol)
= 42.6 kJ/mol.
ΔSvaporization = ΔS(products) - ΔS(reactants)
= 282.6 J/K.mol - 160.6 J/K.mol
= 122 J/K.mol
= 0.122 kJ/K.mol
Using gibbs free energy equation,
ΔG = ΔH - TΔS
ΔG = 0,
T = ΔH/ΔS
T = 42.6/0.122
= 349.18 K.
Coverting Kelvin to °C,
= 349.18 - 273.15
= 76.03 °C.
<h2>Answer:</h2>
He is right that the energy of vaporization of 47 g of water s 106222 j.
<h3>Explanation:</h3>
Enthalpy of vaporization or heat of vaporization is the amount of energy which is used to transform one mole of liquid into gas.
In case of water it is 40.65 KJ/mol. And 18 g of water is equal to one mole.
It means for vaporizing 18 g, 40.65 kJ energy is needed.
So for energy 47 g of water = 47/18 * 40.65 = 106.1 KJ
Hence the student is right about the energy of vaporization of 47 g of water.
Answer:
Explanation:
- For the balanced reaction:
<em>4Fe(s) + 3O₂(g) → 2Fe₂O₃(s).</em>
It is clear that 4 mol of Fe react with 3 mol of O₂ to produce 2 mol of Fe₂O₃.
- Firstly, we need to calculate the no. of moles of 35.8 grams of Fe metal:
no. of moles of Fe = mass/molar mass = (35.8 g)/(55.845 g/mol) = 0.64 mol.
- Now, we can find the no. of moles of O₂ is needed to react with the proposed amount of Fe:
<em><u>Using cross multiplication:</u></em>
4 mol of Fe is needed to react with → 3 mol of O₂, from stichiometry.
0.64 mol of Fe is needed to react with → ??? mol of O₂.
∴ The no. of moles of O₂ needed = (3 mol)(0.64 mol)/(4 mol) = 0.48 mol.
- Finally, we can get the volume of oxygen using the information:
<em>It is known that 1 mole of any gas occupies 22.4 L at standard P and T (STP).</em>
<em></em>
<em><u>Using cross multiplication:</u></em>
1 mol of O₂ occupies → 22.4 L, at STP conditions.
0.48 mol of O₂ occupies → ??? L.
∴ The no. of liters of O₂ = (0.48 mol)(22.4 L)/(1 mol) = 10.752 L.
A covalent bond describes two atoms (most likely nonmetals) that share their valence electrons to satisfy the octet rule. Carbon and oxygen are both nonmetals, and they would share electrons with each other through a bond that is not polar enough to be considered ionic. The answer should be B
