When a molecule absorbs a photon, what is the process called? When a molecule produces a photon, what is the process called?

List the stabilizing forces at tertiary level of protein structure. An enzyme containing the amino aspartic acid (pK_a of the side chain = 3.65) and histidine (pK_a of the side chain= 6) in the active (catalytic ) site has an optimal activity at a pH of 5.0. What is the major stabilizing force at the catalytic site? Using structures and 1-3 complete sentences, predict and explain what is expected to happen to the activity if the pH is increased to 8.

"please answer in details"

A steel sample weighing 1.000 g is dissolved in acids and treated with persulfate and periodate to oxidize Mn to MnO₄^- and Cr to Cr₂O₇^-. The solution is finally diluted to 100.00 mL in a volumetric flask. An aliquot placed in a 1.00-cm cuvette yielded an absorbance of 0.113 at 440 nm and of 1.304 at 545 nm. The absorbance for a reagent blank was 0.005 at 440 nm and 0.008 at 545 nm. Calculate the percentages (m/m) of Cr and Mn in the steel. The molar absorptivity of Cr₂O₇^- is 369 M^-1cm^-1 at 440 nm and 11 M^-1cm^-1 at 545 nm whereas that of MnO₄^- is 95 M^-1cm^-1 at 440 nm and 2350 M^-1cm^-1 at 545 nm. The molar mass of Mn is 54.94 g/mol and that of Cr is 52.00 g/mol.

Calculate the percent ionization in each of the following solutions. a.) 0.10 M NH₃ b.) 0.010 M NH₃

Consider the following reaction:
2SO2(g)+O2(g)→2SO3(g)

What is the theoretical yield of SO3?

If 188.5 mL of SO3 is collected (measured at 327 K and 54.5 mmHg ), what is the percent yield for the reaction?

The first reaction in the Ostwald process for the production of nitric acid involves the combustion of ammonia
4NH3(g)+5O2(g)=4NO(g)+6H2O(g)

a) Estimate ΔH^o (in kJ) for this reaction using average bond energies.

b) Calculate ΔH^o (in kJ) for this reaction using standard heats of formation.

c) Briefly explain why the value for ΔH^o, calculated using average bond energies, is only considered to be an estimate of the standard enthalpy change for the reaction

For the reaction below, Kp = 29.95 at 800 K. Calculate the equilibrium partial pressures of the reactants and products if the initial pressures are P_PCl5 = 0.3900 atm and P_PCl3 = 0.4300 atm. Assume Cl2 is 0 atm. PCL5 (g) > PCl3 (g) + Cl2 (g)

#1. Calculate the pH for each of the following cases in the titration of 50.0 mL of 0.200 M HClO(aq) with 0.200 M KOH(aq). The ionization constant of HClO is Ka = 4.0×10^–8.

(a) Before addition of any KOH

(b) After addition of 25.0 mL of KOH

(c) After addition of 30.0 mL of KOH

(d) After addition of 50.0 mL of KOH

(e) After addition of 60.0 mL of KOH

#2 Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.200 M pyridine, C5H5N(aq) with 0.200 M HBr(aq). The ionization constant for pyridine is Kb = 1.7×10^–9.

(a) Before addition of any HBr

(b) After addition of 12.5 mL of HBr

(c) After addition of 20.0 mL of HBr

(d) After addition of 25.0 mL of HBr

(e) After addition of 29.0 mL of HBr

Calculate the pH of each of the solutions and the change in pH to 0.01 pH units caused by adding 10.0 mL of 2.67-M HCl to 540. mL of each of the following solutions. Change is defined as final minus initial, so if the pH drops upon mixing the change is negative. a) water pH before mixing = Correct: Your answer is correct. pH after mixing= pH change = b) 0.153 M C2H3O21- pH before mixing = pH after mixing= pH change = c) 0.153 M HC2H3O2 pH before mixing = pH after mixing= pH change = d) a buffer solution that is 0.153 M in each C2H3O21- and HC2H3O2 pH before mixing = pH after mixing= pH change =

List and describe three pieces of data that support the fact that octahedral complexes undergo dissociative substitution.

Use the accepted nomenclature to write the name of this compound.

[Ag(o-phen)₂]NO₃

notice that "SO4" appears in two different places in the chemical equation SO-2>4 is a poyatomic ion called sulfate. what number should be placed in front of CaSO4 to give the same total number of sulfate ion in each side of the equation?

Three gases (8.00 g of methane, CH4, 18.0 g of ethane, C2H6, and an unknown amount of propane, C3H8) were added to the same 10.0-L container. At 23.0 ∘C, the total pressure in the container is 3.60 atm . Calculate the partial pressure of propane in the container.

Q.3. What kind of post-translational modifications are taking place on collagen? (there are many. So please check the literature carefully). Why are they important for its structure? In terms of post translational processing of collagen, explain why chicken soup that is liquid when cooked fresh, becomes a gel like material upon refrigeration overnight.

Calculate the average thickness of copper on the surface of a penny (produced after 1983) in units of a.) mm and b.) atoms of Cu. Show all calculations, including unit analysis.