This question is based on the mass spectrum of diethyl sulfide (CH3CH2SCH2CH3) which can be found at this link... http://webbook.nist.gov/cgi/cbook.cgi?ID=C352932&Mask=200 You will need java to see this spectrum! Identify the ion fragment that has a mass of 29.

a) C2H5SC2H5+

b)C4H10+

c) C2H5+

d) S+

Cryogenic liquids (liquid N2, He, etc) are typically stored in Dewar flasks (fancy thermos bottles) that consist of mirrored glass walls (to reduce radiative heating) separated by vacuum (a cylinder within a cylinder). How long would a liter sample of liquid argon last in a flat bottomed cylindrical Dewar with an inner radius of 5cm and height of 20cm and an outer radius of 10cm and height of 25 cm assuming that the only energy transfer that occurs is radiative between the walls of the Dewar (the top surface does not receive any radiation). The emissivity of silvered glass is 0.02 over all wavelengths, the outer surface of the Dewar is at 300K, the temperature of liquid Argon is 87 K, the density of liquid argon is 1.40 g cm3 , and the latent heat of vaporization is 1200 J/g. , The latent heat of vaporization is a measure of how much “extra” energy is required to vaporize a substance at its boiling point (the boiling point of argon is 87K). (Assume that all of the energy impinging on the inner cylinder is used to vaporize the Argon).

Determine the pH of a solution when 21.5 mL of 0.021 M HNO3 is mixed with 17.5 mL of

A) 0.0070 M NaOH.

B) distilled water.

C) 0.0070 M HCl

D) 0.084 M KOH.

compute the following:

(a) Calculate the wavelengths for the Paschen series for Hydrogen

(b) If the average speed of a Hydrogen electron is 4.0*10^6 m/s with a 0.95% uncertainty. What is the uncertainty of its position? ( Hint: the mass of an electron is 9.109*10^-31)

Determine Delta G for the following reactions.

a) Antimony pentachloride decomposes at 448oC. The reaction is: SbCl5(g)-->SbCl3(g)+Cl2(g)

An equilibrium mixture in a 5.00 L flask at 448oC contains 3.85g of SbCl5, 9.14g of SbCl3, and 2.84g of Cl2.

b) Chlorine molecules dissociate according to this reaction: Cl2(g)-->2Cl(g)

1.00% of Cl2 molectules dissociate at 975K and a pressure of 1.00 atm.

calculate the de Brolie wavelength for a molecule of (Ch_4) at -5degree c.

What is the role of kinetic energy quantization in covalent bond formation? [keywords: particle-in-a-box, length, quantum state, energy, kinetic, hydrogen atom, hydrogen molecule, covalent bond energy...]

.   Draw a block flow diagram for a petroleum refinery that includes three different separation processes, five different conversion processes along with one or more finishing processes, and one supporting process to produce altogether nine commercial fuels and materials from a sour crude oil. Clearly label all the feedstocks, processes, and products on your diagram including the type of process (separation, conversion, finishing, and support) and the intermediate products.    Make sure that all processes are correctly connected. Write down the principal objectives of this refinery.

How do quantum mechanics and numbers play into both Bohr's model of the atom and Heisenburg's model?

1.Given the following mole fraction and vapor pressures for miscible liquids A and B, calculate the composition (in mole percentage) of the vapor from a distilling an ideal binary solution at 150°C and 760 mmHg for the solution

X_A=0.50                        P_A=1710mmHg

X_B=0.50                        P_B=130mmHg

2. Define the following.

Refluxing

Dalton’s Law

Raoult’s Law

3. What is the mole fraction of each component if 4.0 g of benzene (C₆H₆) is dissolved in 6.4 g of toluene (C₇H₈)?

4. Consider the following solvent pairs. If mixed together, which pairs would form two layers? If they form two layers, which solvent would be on top?

Acetone and toluene

Methanol and hexanes

Hexanes and methylene chloride

Hexanes and water

5 .Chloroform is an excellent solvent for extracting caffeine from water. The distribution coefficient K_D=(C chloroform)/(C water) for caffeine in chloroform- water is 10 °C at room temperature. Find the mass of caffeine that would be removed from a solution 4.0 g of caffeine in 100ml of water using a single extraction of 100 ml of chloroform.

Calculate the pH of a solution that contains .03 g of NaH2PO4*H2O and .01 g of Na2HPO4*7H2O in 10 mLs.

QUESTION 6 Complete combustion of 4.5892 a particular compound that contains only carbon, hydrogen and oxygen produces 10.4324 g of CO2 and 4.2705 g of H2O. The empirical formula of the compound is given by

C__________________ H______________________ O_____________ (indicate "1" if there is only one atom of a given type in the empirical formula.)

The molar mass of the compound is found to be 116.16 g/mol in a different experiment. What is the molecular formula of the compound?

C______________ H________________ O_____________________

Need help and answers please!

In the qualitative analysis scheme, magnesium and nickel precipitate from solution upon the addition of sodium hydroxide. Once separated from the remaining cations by filtration or decanting, the solid mixture is acidified and warmed to dissolve magnesium and nickel cations back into solution. Adding ammonia creates a buffer solution. (Remember, HCl and NH3 makes for NH4+ cation.) The buffered solution should just be basic (say, pH = 8). Adding sodium hydrogen phosphate (Na2HPO4) precipitates magnesium as MgNH4PO4 (Ksp = 3 x 10-13).

a) Write the Ksp expression for the dissociation of MgNH4PO4.

b) Calculate the molar solubility of the compound in pure water.

c) Calculate the [NH4+] in a pH of 8.

d) Calculate the molar solubility of MgNH4PO4 in a solution with pH of 8.

protein molecules are polypetide chains are made up of amino acids in their phisologically functoning or native state these chains fold in a unique manner such that the nonpolar groups of the amino acids are usually burired in the interior region of the proteins where there is little or no contact with water. when a protein denatures the chain unfolds so that these non polar groups are exposed to water. a useful estimate of the changes of the thermodynamic quantities as a result of denturation is to consider the transfer of hydrocarbon such as methane from an invert solvent to the aqueous enviroment: a) CH4 => CH4 ​(g) b) CH4​=> CH4 (aq) if the values of delta H and delta G are approximately 2.0 kJ/ mol and -14.5 kj/mol respectively for (a) and -13.5 kJ / mol and 26.5 kJ/mol , respectively for b) calulate the values of delta H and delta G for the transfer of 1 mole of CH4 ​according to the equation CH4 =>CH4 (aq) comment on your results assume T = 298 k

A quantity of 6.732 g of an organic compound is dissolved in water to make 270.0 ml of solution. The solution has an osmotic pressure of 1.43 atm at 27 C. The analysis of this compound shows that it contains 41.8% C, 4.7% percent H, 37.3% O, and 16.3% N. Calculate the molecular formula of this compound