Titrate 100.0mL of 0.0500M Fe2+ with 0.100M Ce4+. The equivalence point is when volume of Ce4+ added is 50.0mL. Find the voltage of the cell at the following points: a. 20.0mL b. 36.0mL c. 50.0mL d. 51.0mL e. 63.0mL

The automobile fuel called E85 consists of 85% ethanol and 15% gasoline. E85 can be used in so-called flex-fuel vehicles (FFVs), which can use gasoline, ethanol, or a mix as fuels. Assume that gasoline consists of a mixture of octanes (different isomers of C8H18), that the average heat of combustion of C8H18(l) is 5400 kJ/mol, and that gasoline has an average density of 0.70 g/mL. The density of ethanol is 0.79 g/mL.

Part C Assume that the density and heat of combustion of E85 can be obtained by using 85% of the values for ethanol and 15% of the values for gasoline. How much energy could be released by the combustion of 3.0 L of E85?

(A) The volume of water needed to dissolve 0.0510 grams of magnesium fluoride is ____  L.

Assume no volume change upon addition of the solid.

(B) A 16.3 mL sample of a 0.494 M aqueous nitrous acid solution is titrated with a 0.320 M aqueous potassium hydroxidesolution. What is the pH at the start of the titration, before any potassium hydroxide has been added?

pH = ?

1) Succinyl-CoA inhibits both citrate synthase and α-ketoglutarate dehydrogenase. How is succinyl-CoA able to inhibit both enzymes?

Here are four problems (5 pts each) involving the calculation of DG°' for metabolic reactions we have discussed, based on experimentally determined redox potentials. Calculate the DG°' for each reaction using the equation DG°' = -nFDE₀' and the values for E₀' given in Table 1. Show your work and circle your answer.

Table 1. Reduction potentials for reduction half reactions:

1/2 O₂ + 2H⁺ + 2e^- ® H₂O                                              E₀' = +0.82 V

fumarate + 2H⁺ + 2e^- ® succinate                                  E₀' = +0.03 V

oxaloacetate + 2H⁺ + 2e^- ® malate                                 E₀' = -0.17 V

pyruvate + 2H⁺ + 2e^- ® lactate                                       E₀' = -0.19 V

a-ketoglutarate + CO₂ + 2H⁺ + 2e^- ® isocitrate               E₀' = -0.38 V

FAD + 2H⁺ + 2e^- ® FADH₂                                             E₀' = -0.22 V

NAD⁺ + 2H⁺ + 2e^- ® NADH + H⁺                                    E₀' = -0.32 V

CoQ + 2H⁺ + 2e^- ® CoQH₂                                            E₀' = +0.06 V

Problem 3. malate + NAD⁺ ® oxaloacetate + NADH + H⁺

Problem 4. FADH₂ + CoQ ® FAD + CoQH₂

A buffered solution contains 0.25 M NH3 (Kb = 1.8 x 10-5 ) and 0.40 M NH4Cl.

a. Calculate the pH of this solution.

b. Calculate the pH of the solution that results when 0.20 mole of gaseous HCl is added to 1.0 L of the buffered solution from part a

Determine the Ka of an acid whose 0.364M solution has a pH of 1.80.

Assume for the moment that air consists of 80.00% nitrogen (N2) and 20.00% oxygen (O2) by volume. Use these figures and typical values for temperature and pressure (1.000atm and 25.00°C) to calculate the density of air in g/L.

A. Calculate the pH of a solution formed by combining 0.125 mL of 0.55 M HI with 0.400 mL of 0.14 M KOH at 25°C.
B. Calculate the pH of a solution formed by combining 0.125 mL of 0.55 M HI with 0.400 mL of 0.18 M KOH at 25°C.
C. A 50.00-mL sample of 0.0750 M HCN was titrated with 0.3995 M NaOH. What is the pH of the resulting solution after 5.00 mL of NaOH were added at 25°C? Ka for HCN is 6.2x10–10 at 25°C.
D. A 50.00-mL sample of 0.225 M HCO₂H was titrated with 0.1125 M NaOH. What is the pH at the equivalence point at 25°C?  Ka for HCO₂H is 1.8x10^–4 at 25°C.
E. A 25.00-mL sample of 0.225 M HNO₂ was titrated with 0.1111 M NaOH. What is the pH at the equivalence point at 25°C? Ka for HNO₂ is 7.2x10–4 at 25°C.
F. A solution of 0.600 g of diprotic acid in 100.0 mL of water was titrated with 0.300 M NaOH to the second equivalence point. The volume of the base used was 34.5 mL. What is the molar mass of acid in g/mol?
G. The solubility of Gd₂(SO₄)₃ is 4.0 g/100 mL. What is the Ksp?
H. What is the molarity of Ba²⁺ in a saturated solution of Ba₃(AsO₄)₂? (Ksp = 1.1 x 10^-13)
I. What is the concentration of Mg²⁺ when MgF₂ (Ksp = 6.4 x 10^-9) begins to precipitate from a solution that is 0.20 M F^-?
J. What is the pH of a saturated solution of Pb(OH)₂ (Ksp = 1.2 x 10^-5)?

please answer showing steps ( A to J )

Polystyrene has a statistical segment length of 0.67 nm in the melt and a density of 1.05 g/cm**3.

*find the molecular weight of repeated unit

* Find the characterstic ratio C∞for polystyrene using the known bond distances. Bond lenght of C-Cbond is 0.154nm

* Find the contour length of a PS chain of molecular weight M = 70,000 g/mol.

* Find the persistent length of PS, and give the physical meaning of persistent lenght

Here are four problems (5 pts each) involving the calculation of DG°' for metabolic reactions we have discussed, based on experimentally determined redox potentials. Calculate the DG°' for each reaction using the equation DG°' = -nFDE₀' and the values for E₀' given in Table 1. Show your work and circle your answer.

Table 1. Reduction potentials for reduction half reactions:

1/2 O₂ + 2H⁺ + 2e^- ® H₂O                                              E₀' = +0.82 V

fumarate + 2H⁺ + 2e^- ® succinate                                  E₀' = +0.03 V

oxaloacetate + 2H⁺ + 2e^- ® malate                                 E₀' = -0.17 V

pyruvate + 2H⁺ + 2e^- ® lactate                                       E₀' = -0.19 V

a-ketoglutarate + CO₂ + 2H⁺ + 2e^- ® isocitrate               E₀' = -0.38 V

FAD + 2H⁺ + 2e^- ® FADH₂                                             E₀' = -0.22 V

NAD⁺ + 2H⁺ + 2e^- ® NADH + H⁺                                    E₀' = -0.32 V

CoQ + 2H⁺ + 2e^- ® CoQH₂                                            E₀' = +0.06 V

Problem 1. isocitrate + NAD⁺ ® a-ketoglutarate + CO₂ + NADH

Problem 2. succinate + FAD ® fumarate + FADH₂

Consider a glass electrode or [pH electrode (combination electrode). a. Identify the reference part. b. Identify the indicator part. c. Explain how the potential of the electrode is determined. d. Describe a two-point calibration of the electrode. e. State any five of the eight possible errors that might occur in pH measurements with the electrode.

How much heat energy is required to convert 82.2 g of solid ethanol at -114.5 °C to gasesous ethanol at 129.6 °C? The molar heat of fusion of ethanol is 4.60 kJ/mol and its molar heat of vaporization is 38.56 kJ/mol. Ethanol has a normal melting point of -114.5 °C and a normal boiling point of 78.4 °C. The specific heat capacity of liquid ethanol is 2.45 J/g·°C and that of gaseous ethanol is 1.43 J/g·°C.

Consider the reaction below.

If you start with 0.39 moles of C ₃H ₈ (propane) and 7.0 moles of O ₂, what is the percent yield if 0.51 moles of carbon dioxide is produced?
C ₃H ₈(g) + 5 O ₂(g) → 3 CO ₂(g) + 4 H ₂O(g)

Scientists at the University of Massachusetts at Amherst have used a bacterial organism, known as Geobacter species, in a fuel cell to generate electricity. Describe, in detail, the principle and process of electrical energy generation from bacterial fuel cell. Also include in the discussion major advantages and limitations of bacterial fuel cells.