The volume of the unit cell is 2.67 x 10⁻²⁸ m³.
<h3>What is the volume of a unit cell of a body-centered cubic crystal?</h3>
In a body-centered cubic unit cell, the volume occupied by the particles of the substance is about 68% of the total unit cell.
Assuming that a single atomic a sphere, the volume is:
Volume(atom) = 4/3 x π x r³
Volume(atom) = 4/3 x π x (169 x 10⁻¹²)³
Volume(atom) = 2.02 x 10⁻²⁹ m³
There are a total of 9 atoms in a body-centered unit cell, so the total volume occupied by atoms is:
2.02 x 10⁻²⁹ x 9
= 1.82 x 10⁻²⁸ m³
Volume of cell = (1.15 x 10⁻²⁸ ) / 0.68
Volume of cell = 2.67 x 10⁻²⁸ m³
Therefore, the volume of the unit cell is 2.67 x 10⁻²⁸ m³.
Learn more volume of unit cells at: brainly.com/question/1594030
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The answer is B because <span>It would be useful to memorize that sentence. Once you know that, you can figure out whatever else happens at the anode, the cathode, in the solution, and in the external circuit.</span>
Answer:
-800 kJ/mol
Explanation:
To solve the problem, we have to express the enthalpy of combustion (ΔHc) in kJ per mole (kJ/mol).
First, we have to calculate the moles of methane (CH₄) there are in 2.50 g of substance. For this, we divide the mass into the molecular weight Mw) of CH₄:
Mw(CH₄) = 12 g/mol C + (1 g/mol H x 4) = 16 g/mol
moles CH₄ = mass CH₄/Mw(CH₄)= 2.50 g/(16 g/mol) = 0.15625 mol CH₄
Now, we divide the heat released into the moles of CH₄ to obtain the enthalpy per mole of CH₄:
ΔHc = heat/mol CH₄ = 125 kJ/(0.15625 mol) = 800 kJ/mol
Therefore, the enthalpy of combustion of methane is -800 kJ/mol (the minus sign indicated that the heat is released).
Through hypothesis and experiments