# data[].attributes.body
In calculation of K, what if there is a scenario whereby the constant is too big or too small such that calculator gives Math Error.

# data[].attributes.body
All reactions are reversible, unlike the damage done to my GPA after this mod.

# data[].attributes.headline
Can we use MATLAB to calculate complex equation during exam? Some of us don’t have graphing calculator.

# data[].attributes.subject
Can we use MATLAB to calculate complex equation during exam? Some of us don’t have graphing calculator.

# data[].attributes.body
Hi prof, why do we use the delta Hr value that is for 298K instead of 823K?

# data[].attributes.body
Why is the standard Gibbs free energy of a pure element zero (like O₂ at 25 degrees C)?

# data[].attributes.body
What should I refer ∆𝐶p 0 to as? Is it valid to call it the 'heat capacity of reaction at standard state'?

# data[].attributes.body
Prof, why is K said to be independent of pressure, when it is defined in terms of properties (∆𝐺𝑟 °) set at standard pressure (1 bar)?

Also, ∆𝐺𝑟 ° is also said to be independent of pressure when it is defined in terms of 1 bar. How come?

# data[].attributes.body
Hello prof, may i ask what does the first 2 lines (above the chemical equation) mean, and how will it affect our calculations?

# data[].attributes.body
Hi prof, for this question, how are we to find the dHr / dGr and K@393.15K? I am unable to find Cp values for these species from the tables provided.

# data[].attributes.body
Hi prof, why is the answer suggesting that the operating temperature of a partial condenser is conducted at temperature higher than the Tdew and lower than Tbubble?

# data[].attributes.body
Hi prof, will the formula under point 6) be tested during the final exam?

# data[].attributes.body
Hi Prof, I am still confused about how we can tell if the enthalpy is dependent on temperature or not based on the K values. Should the temperature dependency be taken into account because of the huge discrepancy between the K values in both cases (in the picture above) so it is safer to consider the temperature dependency, or is there another reasoning behind it?

# data[].attributes.body
For part d, why isn't the heat effects of mixing be calculated using change in internal energy since the mixing process was done under rigid tank which means change in internal energy = Q?

# data[].attributes.body
Method of stoichiometry to obtain the composition, does it only apply for gas phase? (extra step needed to obtain liquid phase). I was wondering if we could still use this formula if there are 3 species for the liquid phase reaction question.

# data[].attributes.body
Hi prof, just to double check with you. For the phase rule, the F refers to number of independent variables needed to fix the state of a system. Can the variables either be intensive or extensive?

# data[].attributes.headline
Pollev (Chemical potential of species in the reactant side will be equal to that in product side at equilibrium)

# data[].attributes.subject
Pollev (Chemical potential of species in the reactant side will be equal to that in product side at equilibrium)

# data[].attributes.body
Good morning prof, also wondering why this is not valid, as the chemical potential would be µi*υi, as the chemical potential is defined for each species, so the total for reactant or product side would take into account the stochiometric coefficients.

# data[].attributes.body
Good morning Prof, I would like to ask if the above equation is derived from the dH=TdS + VdP governing equation

# data[].attributes.body
Hi prof, Happy Deepavali. I have one question regarding equilibrium constant. Why is equilibrium constant independent of reaction pressure?

# data[].attributes.body
Hi prof will there be a pollev quiz tomorrow

# data[].attributes.body
Hi prof, can i check for part a, shouldnt acetaldehyde's stoi coefficient be -1 instead of 1?

Also, assuming that acetaldehyde is the product in this case, why is it in part (b), its coefficient become -1

Yes. Stoichiometric number for reactant is negative and product is positive. Please check the enthalpy of formation of acetaldehyde and ethanol from the appendix. The calculation of delta Hr and delta Cp are consistent with the stoichiometric numbers. The stoichiometric number has not changed in (b).

# data[].attributes.body
Effect of P at Constant T
Equilibrium conversion changes based on the sum of stoichiometric numbers
Effect of T at Constant P
Equilibrium conversions changes based on heat effects of the reaction

# data[].attributes.body
Ratio by which reactants and products participate in a chemical reaction.

Ratio will be preserved for a specific reaction.

# data[].attributes.body
Defined based on Gibbs energy of formation of reacting species at standard state and reaction T

Dependent on T and reaction stoichiometry

# data[].attributes.body
Pure species state at 1 bar

Gases: Pure Ideal Gas at 1 bar

Liquids: Pure liquids at 1 bar

Solids: Pure solids at 1 bar

Properties defined based on Standard state

Dependent on T

Independent of P and composition

# data[].attributes.body
Exothermic reaction: K decreases with T

Endothermic reaction: K increases with T

# data[].attributes.body
Defined based on enthalpy of formation of reacting species at standard state and reaction T

Heat Effects of the reaction

Endothermic reaction: Positive
Exothermic reaction: Negative

Dependent on T and reaction stoichiometry

# data[].attributes.body
Solving simultaneously the CRE criterion for each reaction

# data[].attributes.body
Equilibrium composition evaluated by satisfying CRE and VLE criterion

# data[].attributes.body
Equilibrium composition is independent of P (Low to moderate P reactions)

# data[].attributes.body
Equilibrium composition at a given T changes with P

# data[].attributes.body
Defined in terms of standard Gibbs energy change of the reaction

Dependent on reaction stoichiometry and on reaction T

Independent of reaction P and initial amount of species

Related to equilibrium composition (fugacity ratio: reacted state to standard state)

# data[].attributes.body
Rate of forward reaction will be equal to rate of reverse reaction at constant T and P

Total Gibbs energy of the system will be minimum

# data[].attributes.body
Extent to which the reaction has progressed.

Helps to identify the direction of the reaction

Forward reaction: positive
Reverse reaction: negative

Used to evaluate molar composition of species

# data[].attributes.body
Positive for product

Negative for reactant

# data[].attributes.body
Independent variables required to describe the state of the system
F = N - pi + 2 - r