Answer:
A. He arranged the first periodic table.
Explanation:
Answer:
The standard enthalpy of formation of this isomer of octane is -220.1 kJ/mol
Explanation:
Step 1: Data given
The combustion reaction of octane produces 5104.1 kJ per mol octane
Step 2: The balanced equation
C8H18(g) + 12.5 O2 ⟶ 8CO2 (g) + 9 H2O (g) ∆H°rxn = -5104.1 kJ/mol
Step 3:
∆H°rxn = ∆H°f of products minus the ∆H° of reactants
∆H°rxn = ∆H°f products - [∆H°f reactants]
-5104.1 kJ/mol = (8*∆H°fCO2 + 9*∆H°fH20) - (∆H°fC8H18 + 12.5∆H°fO2)
∆H°f C8H18 = ∆H°f 8CO2 + ∆H°f 9H2O+ 5104.1 kJ/mol
∆H°f C8H18 = 8 * (-393.5 kJ)/mol + 9 * (-241.8 kJ/mol)] + 5104.1 kJ
/mol
∆H°f C8H18 = -220.1 kJ/mol
The standard enthalpy of formation of this isomer of octane is -220.1 kJ/mol
Answer:
18 km
Explanation:
To know the distance, you need to be clear in the concept of distance.
According to the physics, the distance is a measurement that refers to the fact of how much an object has move from one point to another.
In this case, we have a person named Steve and he's walking through several points.
To calculate the distance that he moved, you just need to sum all the values of distance. In this case, it's not neccesary to do calculations regarding the components of the x or y axis, because we are not talking about displacement, where it actually counts. But in this case, we just need all the covered distance that Steven walked since the beggining.
So, no more talk, let's do calculations:
D = 5 + 2 + 9 + 2 = 18 km
So the final answer would be:
<h2>
Distance = 18 km</h2>
Hope this helps
The answer is C
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Na-24 and Na-23 have the same number of atoms=11, different neutrons(13 and 12),different mass number(24 and 23)
<h3>Further explanation
</h3>
The elements in nature have several types of isotopes
Isotopes have the same number of protons and having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
number of atoms = 11
mass number = 23
number of neutrons=23-11=12
number of atoms = 11
mass number = 24
number of neutrons=24-11=13
