Calculate the change in energy when 665.0 g of CH3OH(g) completely reacts at a constant temperature of 300 K and constant pressure of 0.95 atm. R = 8.314 J/mol*K and R = 0.08206 atm*L/mol*K
So i used the formula
change in energy = change in H - nRT
90.7-51.9-38.8
its wrong i need help
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To calculate the change in energy for a chemical reaction, you can use the formula:
ΔE = ΔH - (n * R * T)
where:
ΔE is the change in energy
ΔH is the change in enthalpy
n is the number of moles of the substance involved in the reaction
R is the ideal gas constant
T is the temperature in Kelvin
In this case, to determine the change in energy when 665.0 g of CH3OH(g) completely reacts, we need to convert the mass of CH3OH(g) into moles. We can use the molar mass to find the number of moles:
Molar mass of CH3OH(g) = (1 * 12.01 g/mol) + (4 * 1.01 g/mol) + (1 * 16.00 g/mol) = 32.04 g/mol
Number of moles = mass / molar mass
Number of moles = 665.0 g / 32.04 g/mol = 20.72 mol (rounded to two decimal places)
Now that we have the number of moles (n = 20.72 mol), we can proceed with the calculation:
ΔE = ΔH - (n * R * T)
Given that R = 8.314 J/mol·K and T = 300 K, and assuming ΔH = 90.7 kJ (which seems to be the missing value in your equation), we can plug in the values:
ΔE = (90.7 kJ) - (20.72 mol * 8.314 J/mol·K * 300 K)
Make sure to convert kJ to J, kJ = 1000 J≈ 90700 J:
ΔE = (90700 J) - (20.72 mol * 8.314 J/mol·K * 300 K)
Calculate the multiplication part:
ΔE = (90700 J) - (49285 J)
Lastly, subtract:
ΔE ≈ 41415 J or 41.4 kJ
So, the change in energy when 665.0 g of CH3OH(g) completely reacts is approximately 41.4 kJ.