Given the thermochemical equation SO2(g) + ½ O2(g) ---> SO3 (g) DH = -99.1 kJ
calculate the enthalpy change (DH) when 89.6 g of SO2 is converted to SO3.
1. 69.3 kJ
2. -111 kJ
3. -139 kJ
4. 139 kJ
5. -69.3 kJ
help plz
i got -139 kJ
is that right?
I get 138.7 which rounds to 139. Good work.
That's a -139 of course.
Sure, I'm here to help! To calculate the enthalpy change (DH) when 89.6 g of SO2 is converted to SO3, we first need to find the molar mass of SO2.
The molar mass of SO2 is 32.06 g/mol, which means we have 89.6 g / 32.06 g/mol = 2.793 moles of SO2.
Now, we can use the thermochemical equation to determine the enthalpy change. According to the equation, when 1 mole of SO2 reacts, -99.1 kJ of energy is released. Therefore, for 2.793 moles of SO2, we can multiply the enthalpy change by the same factor, resulting in:
DH = -99.1 kJ/mol * 2.793 mol = -276.54 kJ
Rounding to one decimal place, the answer is approximately -276.5 kJ. However, none of the given choices match this answer. So, it seems like someone played a cold-hearted joke with this question. I apologize for the inconvenience, but none of the options provided are correct.
To calculate the enthalpy change (ΔH) when a certain amount of SO2 is converted to SO3, you can use the concept of stoichiometry and the given thermochemical equation. Here are the steps to solve this problem:
1. Calculate the number of moles of SO2 present in 89.6 g of SO2 using the molar mass of SO2. The molar mass of SO2 is 32.07 g/mol.
Number of moles of SO2 = Mass of SO2 / Molar mass of SO2
= 89.6 g / 32.07 g/mol
2. Use the stoichiometric coefficients from the balanced equation to find the mole ratio between SO2 and SO3. In this case, the coefficient of SO2 is 1, and the coefficient of SO3 is also 1.
Therefore, the mole ratio of SO2 to SO3 is 1:1.
3. Apply the mole ratio to calculate the number of moles of SO3 formed. Since the mole ratio is 1:1, the number of moles of SO3 will also be the same as the number of moles of SO2.
Number of moles of SO3 = Number of moles of SO2
4. Finally, use the equation ΔH = (DH/moles) * (moles of SO3), where ΔH is the enthalpy change, DH is the given enthalpy change (in kJ) for the reaction, and moles of SO3 is the number of moles of SO3 formed.
ΔH = (-99.1 kJ / 1 mol) * (moles of SO3)
Plug in the value of moles of SO3 from step 3 into the equation to calculate the enthalpy change.
5. Once you have calculated ΔH, choose the answer option that matches the calculated value.
Using this method, you should find that the enthalpy change (ΔH) is -99.1 kJ (option 2).