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).
Explanation:
I think the correct answer is B
Hope this helped u
The electron is travelling with a velocity of 1.123 × 10⁷m/s if it has a wavelength of 8.20 km.
<h3>How to calculate velocity of an electron?</h3>
The velocity at which an electron travels can be calculated using the following formula:
λ = h/mv
Where;
- H = Planck's constant
- m = mass of electron
- v = velocity of electron
- λ = wavelength
- Planck's constant (h) = 6.626 × 10−³⁴ J⋅s.
- mass of electron (m) = 9.109 × 10−³¹ kg
- wavelength = 8200m
8200 = 6.626×10−³⁴ / 9.109 × 10−³¹V
8200 = 7.3 × 10-⁴V
V = 8200 ÷ 7.3 × 10-⁴
V = 1.123 × 10⁷m/s
Therefore, the electron is travelling with a velocity of 1.123 × 10⁷m/s if it has a wavelength of 8.20 km.
Learn more about velocity at: brainly.com/question/13171879
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Answer:
Partial pressure of CO₂ is 406.9 mmHg
Explanation:
To solve the question we should apply the concept of the mole fraction.
Mole fraction = Moles of gas / Total moles
We have the total moles of the mixture, if we have the moles for each gas inside. (3.63 moles of O₂, 1.49 moles of N₂ and 4.49 moles of CO₂)
Total moles = 3.63 mol O₂ + 1.49 mol N₂ + 4.49 mol CO₂ = 9.61 moles
To determiine the partial pressure of CO₂ we apply
Mole fraction of CO₂ → mol of CO₂ / Total moles = P. pressure CO₂ / Total P
Partial pressure of CO₂ = (mol of CO₂ / Total moles) . Total pressure
We replace values: (4.49 moles / 9.61 moles) . 871 mmHg = 406.9 mmHg
Answer:
To obtain the grams of fat that the ground round has, knowing that it weighs 1.33 pounds we must pass this value to grams. Since 1 pound equals 453.59 grams, 1.33 pounds equals 603.27 (453.59 x 1.33).
Now, to obtain 29 percent of 603.27, we must make the following calculation: 603.27 / 100 x 29, which gives a total of 174.94 grams.
In this way, your reasoning is correct and it is probably a mistake in the book.
