1. You may have already noticed that the shape of your spectrophotometric titration curve is quite different than the shapes of the potentiometric titration curves which you have constructed in earlier experiments. Why? (HINT: Think about the mathematical relationships between pH and concentration and absorbance and concentration . . .).

2. When performing a potentiometric titration it is very important to make a large number of measurements near the endpoint, while for a spectrophotometric titration one actually ignores the measurements obtained near the endpoint. Explain.

3. In order for a photometric method to be used for a titration, what requirement(s) must be met by the titration system?

Calculate the Ecell value at 298K for the cell based on the reaction

Fe³⁺(aq)+ Cr²⁺(aq) --> Fe²⁺(aq)+Cr³⁺(aq)

when [Fe³⁺] = [Cr²⁺] = 1.50x10^-3 M and [Fe²⁺]= [Cr³⁺] = 2.5x10^-4 M?

10.00mL 5% acidity vinegar was used titrate with NaOH whose molarity is 0.1030M.

The vinegar was diluted to make 100.00mL final volume before trtration. If the molar mass of acetic acid is 60.05g/mole and density is 1.00 g/mL. Calculate the mass percent of acetic acid in the original vinegar solution.

A 20.0 mL sample of 0.432 M HBr is titrated with a 0.314 M NaOH solution. The pH after the addition of 35.0 mL of NaOH is __________.

I have an unknown mixture of Benzoic acid, Dimethyl Terephthalate, and Naphthalene dissolved in Dichloromethane. I need to separate the mixture to find the composition using some sort of acid base reation and a distillation. How would I do that? I think that I could use steam distillation to remove the naphthalne but im not really sure on that. Any help would be apprectiated. I start with 25mL of the unknown mixture.

A sample of solid magnesium is heated with an electrical coil. If 165 Joules of energy are added to a 14.5 gram sample initially at 24.3°C, what is the final temperature of the magnesium?

A sample of liquid water is heated with an electrical coil. If 1.04×10³ Joules of energy are added to a 13.2 gram sample initially at 20.7°C, what is the final temperature of the water?

For each of the following categories of compounds, indicate the type of liquid chromatography that could be used to separate analytes in that category. (Drag the appropriate chromatography label to the blank next to the category. Only one label applies to each category, but a label may be used more than once).

Seperation Mode Analyte Category

Fm>2000,soluble in octane,size10 nm

Fm>2000, soluble in butanol, size 100 nm

Fm>2000, soluble in water,nonionic,size 10 nm

Fm<2000, soluble in in ethanol

Fm<2000 , soluble in water, ion-paired

Fm<2000, soluble in water, ionic

Choices:

ion -exchange

Bonded-reverse phase

Adsorption

Bonded normal phase

Molecular exculsion

Give the net ionic equations for the following:

a. AgCl + ZnCl2

b. PbCl2 + Hg2Cl2

c. Cd(NO3)2 + AgNO3

d. HCl + HNO3

e. Hg2(NO3)2 + Hg(NO3)2

A voltaic cell consists of an Al/Al3+ half-cell and a Cd/Cd2+ half-cell. Calculate Ecell when [Cd2+] = 0.00303 M and [Al3+] = 0.47 M. You should use the reduction potentials for Al3+ is -1.66 V and for Cd2+ is -0.40 V.

Consider the reaction A -> products at 312 K.

For this reaction it was observed that the first three half lives were 10.7 h, 5.35 h, and 2.675 h when [A] 2.873M. How long will it take for [A] to decrease by 47%?

Time for [A] to decrease by 47% (in hours) = Anwser is 10.1h need help on how to get this anwser.

15) Name two materials that are theoretically strong enough to build a space elevator.?

Please explain in clear words. Thanks

Starting from the first and second law of thermodynamics, derive the fundamental equation for A in its natural variables. a) Derive the Maxwell relation that s related to this equation. b) Show that for df= gdx + hdy we have an exact equation if:

Without doing detailed calculations, indicate which of the following electron transitions in the hydrogen atom results in the emission of light of the longest wavelength. Explain why.

a. from n = 1 to n = 2

b. from n = 4 to n = 3

c. from n = 1 to n = 6

d. from n = 3 to n = 2

Consider the titration of 100.0 mL of 0.016 M HOCl (Ka=3.5×10?8) with 0.0400 M NaOH.

1) How many milliliters of 0.0400 M NaOH are required to reach the equivalence point?

2) Calculate the pH after the addition of 10.0 mL of 0.0400 M NaOH.

3) Calculate the pH halfway to the equivalence point .

4) Calculate the pH at the equivalence point.

thank you!

The law of mass conservation is another fundamental law in chemistry. this law states that matter can neither be created or destroyed, which means that in a chemical reactions where all the reactant is converted into product, the mass of reactant must be equaly equal to mass of product produced. A) consider 2 precipitation reactions B) experimental procedure that you can use in lab C) contemplate how you might visually represent this data (I) what variables might you need to plot (ii) how would your choice of graph illistrate the law of mass conservation