Piperazine, HN(C4H8)NH, is a diprotic weak base used as a corrosion inhibitor and an insecticide and has the following properties: pKb1=4.22pKb2=8.67 For writing the reactions of this base in water, it can be helpful to abbreviate the formula as Pip: Pip+H2OPipH++H2O⇌⇌PipH++OH−PipH22++OH− The piperazine used commercially is a hexahydrate with the formula C4H10N2⋅6H2O.

Show the titration curve by plotting the following points:

• the initial pH of the solution. (pH=11.23)

• the pH at the 25% neutralization point of the first neutralization (pH=10.26)

• the pH at the 50%neutralization point of the first neutralization. (pH=9.78)

• the pH at the 75% neutralization point of the first neutralization. (pH=9.30)

• the pH at the first equivalence point (pH=7.56)

• the pH at the 25% -neutralization point of the second neutralization. (pH=5.81)

• the pH at the 50% -neutralization point of the second neutralization. (pH=5.33)

• the pH at the 75% -neutralization point of the second neutralization. (pH=4.85)

• the pH at the second equivalence point.(pH=3.35)

Be sure to plot all nine points. (Find the HCl volumes of the pH's in mL. Also plot points on graph.)

The atmosphere slowly oxidizes hydrocarbons in a number of steps that eventually convert the hydrocarbon into carbon dioxide and water. The overall reactions of a number of such steps for methane gas is as follows: CH4(g)+5O2(g)+5NO(g)→CO2(g)+H2O(g)+5NO2(g)+2OH(g) Suppose that an atmospheric chemist combines 145 mL of methane at STP, 885 mL of oxygen at STP, and 55.0 mL of NO at STP in a 2.0 −L flask. The reaction is allowed to stand for several weeks at 275 K.

If the reaction reaches 92.0% of completion (92.0% of the limiting reactant is consumed), what are the partial pressures of each of the reactants in the flask at 275 K?

For the reaction shown, compute the theoretical yield of the product in grams for each of the following initial amounts of reactants.
Ti(s)+2F2(g)→TiF4(s)

a. 1.0 gTi; 1.0 gF2

b. 4.8 gTi; 3.2 gF2

c. 0.388 gTi; 0.341 gF2

Express your answer using two significant figures.

To make 10X gel electrophoresis running buffer, 30.0 g Tris base, 144.0 g glycine, and 10.0 g SDS must be dissolved into 1000 mL water. The working stock is a 1X concentration. a. What is the concentration in % w/v of each of the 3 reagents in the 10X stock? b. Describe how you would make 1 L of a 1X working stock solution. c. If 50 mL of the 1X working stock are used to run a gel, how many grams of each of the 3 reagents are in the 1X solution?

Why is charcoal sometimes used in recrystallizations? How does it function? Why should you avoid using large amounts? "Activated carbon" is used in air and water purifiers. How does it work?

1a- Discuss the vaporization of water in standard condition at 298 K in term of: - exothermicity and endothermicity - change of entropy of the system and the surrounding - spontaneity of the reaction.

1b- Explain how the temperature and the composition of the two phases (liquid and vapour) influence the spontaneity of the vaporization of water.

Nitrous acid, HNO2, has a Ka of 7.1 x 10-4. What are (H3O+), (NO2-), and (OH-) in 0.700M HNO2?

a)   (H3O+)=.........M…………………………answer a in M

b))   (NO2-)=..........M…………………………answer b in M

c)   (OH-)..............x 10 .......M...........( answer c   in scientific notation)

This is a multi-part question.

You wish to do a quantitative analysis of chromium metal in the chemical form of potassium dichromate, K2Cr2O7, which visually is a very bright and rich orange color.

Part 1: What is the approximate "true" color of its absorption?

Part 2: What is the approximate wavelength of this "true" absorption?

Part 3: What is the approximate frequency of this absorption?

Part 4: What is the approximate energy of this absorption?

Part 5: What effect is this light having on the compound?

Calculate the alpha values for tartaric acid at pH values of: 0.00, 2.00, 4.00, 6.00, 8.00

Provide a detailed description of the theory of Luminescence spectroscopy and explain (in general terms) how it used in the field of physical chemistry.

Complete and balance the following equations, and identify the oxidizing and reducing agents. (Recall that the O atoms in hydrogen peroxide, H2O2, have an atypical oxidation state.)

1. Complete and balance the following equations:

NO2−(aq)+Cr2O72−(aq)→Cr3+(aq)+NO3−(aq) (acidic solution)

Cr2O72−(aq)+CH3OH(aq)→HCO2H(aq)+Cr3+(aq) (acidic solution)

BrO3−(aq)+N2H4(aq)→Br2(l)+N2(g) (acidic solution)

NO2−(aq)+Al(s)→NH4+(aq)+AlO2−(aq) (basic solution)

H2O2(aq)+ClO2(aq)→ClO2−(aq)+O2(g) (basic solution)

Express your answer as a net chemical equation including phases.

Liquid chlorotribromethane has a density of 2.71 g/mL. A barometer is constructed using chlorotribromethane instead of mercury. If the atmospheric pressure is 0.953 atm, what is the height of the chlorotribromethane column in the barometer in cm?
the density of liquid mercury is 13.6g/mL

A prevailing of one standard atmosphere will support a column of mercury 760 mm in height. Liquid 1,2,3-trichlorobutane has a density of 1.32g/mL. The height of a column of 1,2,3-trichlorobutane that one standard atmosphere can support is ____mm.
The density of liquid mercury is 13.6g/mL.