Consider the dissociaton of methane, into the elements H2g and C(s) given

a) the change of enthalpy of reaction is -74.85 kJ/mol and change of entropyof reaction is -80.67 J/mol K at 298K. Calculate the Keq at 298K.

b) Assuming that change in enthalpy of formation is independent of temperature, calculate K at 323K.

c) Calculate the degree of dissociation of methane at 298K and Ptotal at 0.01 bar.

Using 1.8*10^-5 for the Ka for acetic acid, along with the weight of sodium acetate and volume of acetic acid used to prepare a buffer, calculate the expected pH of the buffer.

So the weight is 4.0089 g and the volume is 100mL

Many different ways have been proposed to make batteries. One cell is set up with copper and lead electrodes in contact with CuSO4(aq) and Pb(NO3)2 (aq), respectively. If the Pb2+ and Cu2+ concentrations are each 1.0 M, what is the overall cell potential?

Pb2+ + 2e- ---> Pb E = -0.22 V

Cu2+ + 2e- ----> Cu E = +0.34 V

answer: 0.56 V. how?

Q.N.2) A portion of a specicific DNA molecule consists of the following sequence of nucleotide triplets:

TAC   GAA    CTT  CGG

What is the DNA sequence codes for this terapeptide?

. Consider the following reduction-oxidation “skeleton” equation,

Br2(l) = BrO3 ‒ (aq) + Br‒ (aq)

a. Write a balanced equation for the reduction-oxidation reaction that occurs in basic solution.

b. Using your balanced equation, identify the chemical species that is: (1) oxidized, (2) reduced, (3) the reducing agent, and (4) the oxidizing agent.

How many oxygen atoms are present in 373 g of mannose, C6H12O6?

Calculate the pH for each of the following cases in the titration of 50.0 mL of 0.170 M HClO(aq) with 0.170 M KOH(aq). The ionization constant for HClO can be found here.

At constant volume, the heat of combustion of a particular compound is –3680.0 kJ/mol. When 1.029 g of this compound (molar mass = 150.46 g/mol) was burned in a bomb calorimeter, the temperature of the calorimeter (including its contents) rose by 4.773 °C. What is the heat capacity (calorimeter constant) of the calorimeter?

Why is kcat not necessarily the best way to evaluate or compare the activities of two enzymes? What “adjustment” can be made to make the term more useful and why? A) Define the rate constants k1, k2 and k-1. Given k1 of 2x10^-8/M s, k2 of 5x10^3/s, and k-1 of 1x10^3/s, what is KD? what is KM? B) Which substrate is preferred: R, for which enzyme X has a KM of 2mM? OR Q, for which X has a KM is 7mM? Explain. If k2 for Q is 2x10^4/s and for R is 4x10^5/s, which substrate yields the best catalytic efficiency? Explain.

3)Suppose a solution is prepared by dissolving 15.0 g NaOH in 0.150 L of 0.250 M nitric acid. What is the final concentration of OH- ions in the solution after the reaction has gone to completion. Assume that there is no volume change when adding the grams of NaOH.

100 mL of buffer solution that is 0.15M HA (K_a= 6.8x10^-5) and 0.20M NaA is mixed with 34.8mL of 0.35M NaOH. What is the pH of the resulting solution?

Consider the titration of 100.0 mL of 0.42 M H₃A by 0.42 M KOH for the next three questions. The triprotic acid has K_a1 = 1.0 x 10^-4, K_a2 = 1.0 x 10^-7, and an unknown value for K_a3. All answers to 3 significant digits.

1) Calculate the pH after 100.0 mL of KOH has been added.

pH =

2) Calculate the pH after 150.0 mL of KOH has been added.

pH =

3) The pH of the solution after 200.0 mL of KOH has been added is 9.00. Determine the value of K_a3 for this triprotic acid. Use scientific notation to enter this answer, e.g., 1.0 x 10^-3 = 1.0E-3.

Ka₃ =

Consider a solution that is 2.1×10^?2 M in Fe2+and 1.8×10^?2 M in Mg2+.

I know that the Fe2+ was the first to precipitate and that the minimum concentration of K2CO3 is

What I need to know is What is the remaining concentration of the cation that precipitates first, when the other cation just begins to precipitate?

MnO2 (s) + 2 CO (g) → Mn (s) + 2 CO2 (g)

5. Calculate ΔG at 298K if MnO2 = 0.150 mol, Mn = 0.850 mol, CO = 0.250 M and CO2 = 0.500 M in a 1.25 L flask.

This question has already been answered, but there was not as much detail as i needed to understand what exactly to do and i need to understand it quick... could you please walk me through how to do this, but specifically A and B please plug in all numbers and state where they came from , thank you so much!

Calculate the potential in the following cell

Pb|Pb2+(1.00M)|| Ag+(1.00M) |Ag

a. right at the beginning when you start using this voltaic cell,

b. when 50% of the Ag+ ions have been consumed,

c. when 99% of the Ag+ ions have been consumed, and

d. when 99.99% of the Ag+ ions have been consumed. Keep in mind that both, the Pb2+ and the Ag+ concentrations are changing.