A beaker with 1.90×102 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 7.70 mL of a 0.430 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740.

What is an extinction coefficient? Why is it different for each protein? Show how you would convert an extinction coefficient in M-1 cm-1 units to mg-1 mL cm-1 and how you would convert an extinction coefficient in %-1 cm-1 to mg-1 mL cm-1

A.) A piston has an external pressure of 5.00 atm. How much work has been done in joules if the cylinder goes from a volume of 0.170 liters to 0.570 liters?

B.) An ideal gaseous reaction (which is a hypothetical gaseous reaction that conforms to the laws governing gas behavior) occurs at a constant pressure of 35.0 atm and releases 73.8 kJ of heat. Before the reaction, the volume of the system was 7.00 L . After the reaction, the volume of the system was 3.00 L .

Calculate the total internal energy change, ΔE, in kilojoules.

C.)

An ideal gas (which is is a hypothetical gas that conforms to the laws governing gas behavior) confined to a container with a massless piston at the top. (Figure 2) A massless wire is attached to the piston. When an external pressure of 2.00 atm is applied to the wire, the gas compresses from 4.40 to 2.20 L . When the external pressure is increased to 2.50 atm, the gas further compresses from 2.20 to 1.76 L .

In a separate experiment with the same initial conditions, a pressure of 2.50 atm was applied to the ideal gas, decreasing its volume from 4.40 to 1.76 L in one step.

If the final temperature was the same for both processes, what is the difference between q for the two-step process and q for the one-step process in joules?

D.) A volume of 120. mL of H2O is initially at room temperature (22.00 ∘C). A chilled steel rod at 2.00 ∘C is placed in the water. If the final temperature of the system is 21.40 ∘C , what is the mass of the steel bar?

Use the following values:

specific heat of water = 4.18 J/(g⋅∘C)

specific heat of steel = 0.452 J/(g⋅∘C)

E.) The specific heat of water is 4.18 J/(g⋅∘C). Calculate the molar heat capacity of water.

A.) Mothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 1.025 g of naphthalene is burned in a bomb calorimeter, the temperature rises from 24.25 ∘C to 32.33 ∘C.

Calculate the standard enthalpy of formation (ΔH∘f) for nitroglycerin. Express the change in energy in kilojoules per mole to three significant figures.

B.) The air within a piston equipped with a cylinder absorbs 575 J of heat and expands from an initial volume of 0.12 L to a final volume of 0.83 L against an external pressure of 1.0 atm.

What is the change in internal energy of the air within the piston?

C.) A 2.95 g lead weight, initially at 10.8 ∘C, is submerged in 8.07 g of water at 51.9 ∘C in an insulated container. What is the final temperature of both the weight and the water at thermal equilibrium? Express the temperature in Celsiu

D.) Suppose that 24 g of each of the following substances is initially at 26.0 ∘C. What is the final temperature of each substance upon absorbing 2.40 kJ of heat?

gold

silver

aluminum

water

1. What does the number of drops of ammonia water indicate? In other words, what is their significance, such as if they were the same for all trials or if they differed?

2.Explain chemically why you could not repeat the step indefinitely.

3, Using Le Chatelier's Principle, discuss and explain your results for when you altered the procedure.

For the reaction A + B + 2C = 3D at 25 Celsius, the following initial rate data were obtained:

Experiment #1: [A] = 0.1M, [B] = 0.1M, [C] = 0.2M, Initial Rate of Formation for D = 4 e -4 M/min

Experiment #2: [A] = 0.3M, [B] = 0.2M, [C] = 0.2M, Initial Rate of Formation for D = 1.2 e -3 M/min

Experiment #3: [A] = 0.1M, [B] = 0.3M, [C] = 0.2M, Initial Rate of Formation for D = 4 e -4 M/min

Experiment #4: [A] = 0.3M, [B] = 0.4M, [C] = 0.6M, Initial Rate of Formation for D = 3.6 e -3 M/min

If Experiment #2 is repeated at 50 Celsius and the initial rate is measured to be 1.6 e -3 M/min, what is the activation energy?

PLEASE PROVIDE ALL STEPS! :)

Why does solid 1-indanone and 3,4-dimethoxybenzaldehyde become liquids with mixed together? Explain this phenomena using chemical terms.

Consider the titration of a 28.0 −mLsample of 0.180 M CH3NH2 with 0.155 M HBr. Determine each of the following.

the inital pH

the volume of added acid required to reach the equivalence point

the pH at 6.0 mL of added acid

the pH at one-half the equivalence point

the pH at the eqivalence point

the pH after adding 6.0 mL of acid beyond the equivalence point

Once the stock solutions are prepared, describe how you would produce your buffers (four). Your explanation should be detailed and quantitative.

For my stock solution:

KH2PO4 = (136.08 g/mol)(1M)(100.00ml/1000ml)= 13.608 gm

            K2HPO4 = (174.17 g/mol)(1M)(100.00ml/1000ml)= 17.4178 gm

KH2PO4= (136.08 g/mol)(1M)(250.00ml/1000ml)= 34.02 gm

K2HPO4= (174.17 g/mol)(1M)(250.00ml/1000ml)= 43.54 gm

            KH2PO4= (136.08 g/mol)(1M)(25.00ml/1000ml) = 3.402 gm

            K2HPO4= (174.17 g/mol)(1M)(25.00ml/1000ml) = 4.35425 gm

KH2PO4= (136.08 g/mol)(1M)(10.00ml/1000ml)= 1.3608 gm

K2HPO4= (174.17 g/mol)(1M)(10.00ml/1000ml)= 1.74178 gm

            KH2PO4= (136.08 g/mol)(1M)(5.00ml/1000ml)= 0.6804 gm

            K2HPO4= (174.17 g/mol)(1M)(5.00ml/1000ml)= 0.87085 gm

Calculate the percent yield of the aldol condensation-dehydration reaction.

I did the following

Put 0.8 mL aldehyde, 0.2 mL ketone, 4 mL ethanol, 3 mL of 2M sodium hydroxide in a flask. Then swirled it for 15 min. Then I added 6 mL ethanol and 4 mL of 4% acetic acid. I put the solution on ice and crystals formed. I ended up with 0.305 g of product. Please show me how to calcualte my percent yield for my product.

Consider the following reaction at 215 K: 2 A (aq) + 1 B (aq) → 1 C (aq) + 1 D (aq)

An experiment was performed with the following intitial concentrations: [A]i = 1.37 M, [B]i = 2.03 M, [C]i = 0.65 M, [D]i = 0.11 M.

The reaction was allowed to proceed until equilibrium was reached at which time it was determined that [A] = 0.61 M. What was the maximum amount of work that could have been performed as the reaction began? Maximum amount of work performed as the reaction began (in kJ)=

A solution prepared by mixing 50.2 mL of 0.280 M AgNO3 and 50.2 mL of 0.280 M TlNO3 was titrated with 0.560 M NaBr in a cell containing a silver indicator electrode and a reference electrode of constant potential 0.175 V. The reference electrode is attached to the positive terminal of the potentiometer, and the silver electrode is attached to the negative terminal. The solubility constant of TlBr is Ksp = 3.6 × 10–6 and the solubility constant of AgBr is Ksp = 5.0 × 10–13..

What is the cell voltage when the following volumes of 0.560 M NaBr have been added?

(b) 1.0 mL (c) 16.1 mL (d) 24.1 mL (e) 25.0 mL (f) 25.4 mL (g) 41.2 mL (h) 50.2 mL (i) 57.2 mL

Please show step by step

physical chemistry problems using excel:

#1 Use Excel (or another graphing program) to plot the 2s and 2p radial wavefunctions (R). Determine where the nodes in these functions occur. Plot the square of the radial wavefunctions (R^2) for the 2s and 2p orbitals of a hydrogen atom. By differentiation, determine where the maxima in square of the radial wavefunction (R^2) occur for these orbitals. Physically, what do the maxima of R^2 represent?

#2 Use Excel to plot the 2s and 2p radial distribution functions. What are the most probable radii that a 2s and 2p electron will be found? Why are these values different than that calculated in 1?

Write a chemical equation for HCl(aq) showing how it is an acid or a base according to the Arrhenius definition.

Write a chemical equation for NH4+(aq) showing how it is an acid or a base according to the Arrhenius definition.

Write a chemical equation for Ba(OH)2(aq) showing how it is an acid or a base according to the Arrhenius definition.

Write a chemical equation for HC2H3O2(aq) showing how it is an acid or a base according to the Arrhenius definition.

1- why is method development easier with gradient elution chromatography than isocratic separations?2- in some detail explain why one would use elevated temperatures in liquid chromatography ? 3- what is DryLab and why use it? please give me refrences?