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.

Use the particle in a box model to estimate the energies of the first electronicallyexcited states of ethylene, butadiene and hexatriene. Use a table of bond lengths to estimate the length of the box

The following data was taken in a GC experiment: tr of air (non retained) = 33s, tr of benzene = 275s, tr of toluene = 342s. From the literature it is known that the partition coefficient of benzene for the stationary phase in your column and at your column temperature is 650. Calculate K for toluene.

1) calculate the concentration of maleic acid solution?given : 25.00 mL of maleic acid of unknown contration is diluted with 50.00 mL of water. It is used to titrate 49.72mL of 0.1 M NaOH solution.

2)calculate the concentration of the diluted and undiluted CH3COOH (aq) solution.
given: 25.00 mL of unknown acetic acid solution is diluted with 50.00 mL water. It is used to titrate 49.83 mL of 0.1 M NaOH solution

A compound with molecular mass = 292.16 g/mol was dissolved in a 5.000 mL volumetric flask. A 1.000 mL aliquot was withdrawn, placed in a 10.000 mL flask and diluted to volume. The apparent absorbance of the diluted solution at 340 nm was 0.827 in a 1.000 cm cuvette. To check for a possible stray light effect, this sample was diluted by exactly a factor of 2; the apparent absorbance was now 0.421. A reagent blank showed negligible absorbance. The (true) molar absorptivity at 340 nm = 2.130 x 104 M-1 cm-1.

a) Estimate the stray light in the spectrophotometer.

b) Calculate the concentration of the compound in the cuvette.

c) What mass of the compound was used to make the solution in the 5.000 mL flask?

1. Design your own environmental laboratory experiment based on ANY of the labs we completed during CE 4371. You will be graded based on:
   1. Developing your overarching experimental question/goal,
   2. How you appropriately select your experiments to answer your question, and
   3. Your thought process of what your outcome will likely be and why.

Please be sure to detail your sampling procedures, where your samples will be collected from, how you will analyze your data, and what data will be collected in your theoretical data sheet. You can expand upon our experiments in lab. For example, if you want to measure more than just Fe on the AA machine, you can select copper, arsenic, etc., as long as it is measurable on an AA machine.

is just theoretical. You do not actually have to perform the experiment. Therefor, it phosphorus is very interesting to you, and hypothetically you are interested in how much phosphorus run off the farm produces, you would write down the sample collection procedure and the phosphorus testing procedure

1. A 30 g piece of metal (160.9 g/mol) melts at 1,560°C and its enthalpy of fusion is 12.6 kJ/mol. Calculate the entropy of fusion (J/k) per mole of the metal.

2. The temperature of a 374 g piece of granite is increased from 38.4°C to 62.6°C. What is its change in entropy (J/K)? The specific heat capacity of granite is 0.790 J/g^.K.