A student wishes to determine the chloride ion concentration in a water sample at 25 °C using a galvanic cell constructed with a graphite electrode and a half-cell of AgCl(s) + e⁻ → Ag(s) + Cl⁻(aq) E°red = 0.2223 V And a copper electrode with 0.500 M Cu²⁺ as the second half cell Cu²⁺(aq) + 2 e⁻ → Cu(s) E°red= 0.337 V The measured cell potential when the water sample was placed into the silver side of the cell was 0.0657 V.

What is the standard potential of the cell?

What is the value of standard free energy (in kJ) for this reaction?

What is the balanced equation for the overall reaction in acidic solution?

The measured cell potential is 0.0657, what is the concentration of chloride ions in the solution?

Calculate BOD5 of all 3 samples.

How will you prepare 250 mL of 0.01 M NaOH from NaOH pellets? Please describe in detail how to properly handle, weight, and dissolve the NaOH pellets, and how you would store the solution

Compressibility, τ, is defined as: τ = − 1 /ν *(dν/ dp) Show that the ratio of the isothermal compressibility to the isentropic compressibility is equal to the specific heat ratio for a perfect gas.

If a histidine sidechain in a binding site is protonated in the free protein, but deprotonated in the ligand-bound state, how would pH affect the interaction?

A.) No effect

B.) Lower Kd at lower pH

C.) Higher Kd at lower pH

D.) Only ΔH would change with pH

Consider the diprotic acid h2a with k1=1.00x10-4 and k2=1.00x10-8. find the pH and concentrations of h2a, ha-, and a2- in (a) 0.100 M H2A (b) 0.100 M NaHA (c) 0.100 M Na2A

Le Chatelier's principle states that a chemical system must have a shift in direction in order to force the system to reach equilibrium.

a.true

b.false

Calculate the mass of ammonium chloride required to prepare 25 mL of a 2.0 M solution, and the mass of calcium chloride required to prepare 25 mL of a 2.0 M solution.

A 100 mg vitamin C tablet weighed 1.627 g. A student crushed the tablet and transferred 0.159 g of the crushed powder into a 100 mL volumetric flask, dissolved the powder in ~30 mL DI water, then filled the flask to the calibration line with DI water and mixed well to create Solution 1. The student then transferred 23.2 mL of Solution 1 into a 100 mL volumetric flask and diluted to the calibration line with DI water to create Solution 2. Calculate the expected concentration (in mM) of ascorbic acid in Solution 2.

The three reactions below are all at equilibrium simultaneously in solution.
Ca2+ (aq) + C2O42- (aq) « CaC2O4 (s)

H2C2O4(aq)«H+(aq)+HC2O4-(aq)

HC2O4- (aq) « H + (aq) + C2O42- (aq)
a. If HNO3 is added to this solution, would you expect to see more or less of the precipitate (CaC2O4) formed in the solution? Explain your reasoning by showing the effect of the addition of HNO3 on the equilibrium for the reaction.

1. Calculate the volume in milliliters (mL) of a 6.00 M NaOH solution needed to make 5.00 x 102 mL of a 0.100 M NaOH solution. (Recall that M = molar = mol/L, and show all your work).

2. An approximately 0.1 M NaOH solution was standardized with KHP by titration to a phenolphthalein endpoint. From the following data, calculate the average molarity of the NaOH. The molar mass of KHP is 204.22 g/mol.

Trial 1 Trial 2 Mass of weighing paper + KHP 2.1467 g 2.1719 g Mass of weighing paper 1.4125 g 1.4136 g Mass of KHP __________ __________ Moles of KHP __________ __________ Final buret reading 31.80 mL 32.67 mL Initial buret reading` 0.15 mL 0.04 mL Volume of NaOH (mL) __________ __________ Molarity of NaOH (moles per liter) __________ __________ Average molarity __________

3. Calculate the average molarity, standard deviation (SD), and percent (%) variation of the three titration molarities given below. Recall: % variation = (SD/mean)*(100%).

Molarity of HCl: 0.3087 M 0.3083 M 0.3092 M

Average Molarity: ___________________ ± _____________ (SD) [UNITS!]

Percent (%) variation: ____________________ %

Is the percent variation less than 1%? _________

Why does the nitration of bromobenzene form ortho and para products in an Electrophilic Aromatic Substitution reaction?

Find an example of a detergent. Using a line drawing, draw the detergent and provide its name.