For which of the following reactions is ?H?rxn equal to ?H?f of the product(s)?

You do not need to look up any values to answer this question. Check all that apply.

SO(g)+12O2(g)?SO2(g)

2Na(s)+F2(g)?2NaF(s)

Na(s)+12F2(g)?NaF(s)

S(s)+O2(g)?SO2(g)

Na(s)+12F2(l)?NaF(s)

SO3(g)?12O2(g)+SO2(g)

the Santa Ana winds are strong within Southern California. what drives this phenomenon?
(use thermodynamic quantities/concepts to explain)
Physical chemistry question

Capsaicin is the compound that makes hot peppers spicy. This compound reversibly binds to the same protein that detects heat in our bodies. For that reason, when we eat spicy food we experience a “burning” sensation. The spice level in different types of peppers is measured in Scoville units. A Scoville unit refers to the number of times a pepper extract has to be diluted in order for a panel of people to no longer detect the heat. For example, a Jalapeño pepper ranks about ~5000 units. This means that liquid extracted from a Jalapeño must be diluted 5000 times before the heat is no longer detectable to the palate.

The spiciest peppers known, such as the Carolina Reaper, have about 3 million Scoville units of heat. Imagine you watch a show on TV claiming that the Carolina Reaper pepper is 600 times spicier than a Jalapeño (3 million divided by 5 thousand), since you know the thermodynamics of chemical equilibria, you can make a more nuanced assessment of that claim.

Explain why or why not the TV host above might or might not be correct. Clearly state any assumptions and use equations if necessary.

Ionization is removal of an electron from the ground state [lowest possible value of n] completely from the atom. Calculate the energy required to ionize a hydrogen like atom (in kJ/mol).

The reaction is: Mg(s) + 2HCl(aq) --> MgCl2 (aq) + H2(g)

1. If 2.016 g of hydrogen (H2) was released, how many moles of magnesium reacted? How many grams of magnesium would this be?

2. How many moles of magnesium would replace one mole of hydrogen (H) in the hydrochloric acid? How many grams? (This is the equivalent weight)

3. Compare the mass calculated above in question 2 to your experimental equivalent weight and calculate the percent difference. What would cause your experimental value to be different? %difference = [(calculated value-experimental value)/(calculated value)]x100

4. Using the ideal gas law, calculate the value of R in L-atm/mol-K by assuming that an ideal gas occupies 22.4 L/mol at STP.

A. Calculate the density of sulfur hexafluoride gas at 706 torr and 20 ?C.

B. Calculate the molar mass of a vapor that has a density of 7.130 g/L at 13 ?C and 744 torr .

What is the pH of 0.41 M H₃PO₄? The K_a values for phosphoric acid are K_a1 = 7.5×10-3, K_a2 = 6.2×10-8, and K_a3 = 3.6×10-13.

A voltaic cell consists of a Pb/Pb2+ half-cell and a Cu/Cu2+ half-cell at 25 ∘C. The initial concentrations of Pb2+ and Cu2+ are 5.20×10⁻²M and 1.50 M, respectively.

A) What is the cell potential when the concentration of Cu2+ has fallen to 0.250 M ?

B) What are the concentrations of Pb2+ and Cu2+ when the cell potential falls to 0.36 V?

1)Info:
a)Consider the equilibrium:
Ag (NH3)2^+ + Cl^- <------> AgCl + 2NH3

b) Based on the stoichiometry of the reaction, which of the conditions constitutes an excess of NH3 over Cl-? (3:1 or 30:1)
     Both ratios work
       ~~~~~~~~~~~~~~~~~~~~~~~~
Question:
c) Based on your answer to part (b), which ion (Cl-/NH3) forms a stronger bond to Ag+. State your reasoning.

d) Derive and calculate the Keq value for the equilibrium above (part (a)) using the following values of the equilibrium constants:
Kf[Ag (NH3)2+] = 1.7 x 10^7 and
Ksp(AgCl) = 1.7 x 10^-10

Describe the influences and forces driving the formation of the lipid bilayer. Briefly
discuss the effect of a phase transition on a lipid bilayer.

12.

a) Consider a sample of hemoglobin molecules all bound to carbon monoxide CO. What conformation would be favored? What would the Hill plot of that sample look like?

b Consider a sample of hemoglobin molecules all bound to BPG. What conformation would be favored? What would the Hill plot of that sample look like?

In the simple distillation of a mixture of toluene and cyclohexane, the average highest temperature recorded was in 95 degrees Celsius. Explain why in the fractional distillation of the same mixture, the average highest temperature was 108 degrees Celsius.

The molality of an aqueous sodium nitrate solution is 2.81 m. What is the mole fraction of NaNO3? The molar mass of NaNO3 is 85.00 g/mol; the molar mass of water is 18.02 g/mol. 0.0506 0.239 0.00281 0.193 0.0482