Ethylene glycol, formula C2H6O2, is used as antifreeze for automobiles and is sometimes mixed with water at a 1:1 ratio by volume and produces a solution with a density of 1.07 g/mL. Assume that the solution behaves ideally. Notes: at 25 oC the densities of water and ethylene glycol are 1.00 g/mL and 1.11 g/mL, respectively, the vapor pressures of water and ethylene glycol at 20 oC are 17.54 torr and 0.06 torr, respectively, and Kb and Kf of water are 0.51 K/m and 1.86 K/m, respectively.

a. What is the freezing point of this solution?

b. What is the vapor pressure, in torr, of this solution at 20 oC?

c. What is the osmotic pressure, in atm, of this solution at 25 oC and 0 oC?

d. What is the mass percent (m/m)% of this solution?

The ability of an atom in a molecule to pull bonding electrons toward itself is:

a)Paramagnetism

b)Diamagnetism

c)Effective nuclear charge

d)Electronegativity

e)Ionization potential

Given the electronegativity values below, select the single bond that is LEAST polar.

Element: H C N O

Electronegativity: 2.1 2.4 3.0 3.5

a) N-H

b) C-H

c) O-N

d) O-C

e) O-H

Imagine that you grew a shiny crystal of a brand new compound X. How would you determine: (a) the crystal structure of X (b) whether this material is a semiconductor or not

Balance the skeleton redox reaction. Write the oxidation state of each compound above the redox symbol, show each redox couple/half reaction. Show both the acidic and basic state. The answer must demonstrate the use of the half reaction method. H5IO6 (aq) + I2 (aq) → IO3 - (aq)

A solution is prepared in which 0.00100 mol of Ni(NO3)2 and 0.500 mole of NH3 are dissolved in a total volume of 1.00 L. What is the concentration of Ni(H2O)62+ ions in the solution at equilibrium?

A 2.800×10−2 M solution of NaCl in water is at 20.0∘C. The sample was created by dissolving a sample of NaCl in water and then bringing the volume up to 1.000 L. It was determined that the volume of water needed to do this was 999.2 mL . The density of water at 20.0∘C is 0.9982 g/mL.

1a) Calculate the molality of the salt solution. Express your answer to four significant figures and include the appropriate units.

1b) Calculate the mole fraction of salt in this solution. Express the mole fraction to four significant figures.

1c) Calculate the concentration of the salt solution in percent by mass. Express your answer to four significant figures and include the appropriate units.

1d) Calculate the concentration of the salt solution in parts per million. Express your answer as an integer to four significant figures and include the appropriate units.

For each of the substances in below classify it as a strong or weak electrolyte and state whether it exists in solution as molecules, ions, or a mixture of both molecules and ions.

a) hypochlorous acid

      b) strontium hydroxide

      c) perchloric acid

      d) butanoic acid

The thermal decomposition of dimethyl ether CH 3 2 O g CH 4 g H 2 g CO g is to be carried out in an isothermal 2.00-liter laboratory reactor at 600°C. The reactor is charged with pure dimethyl ether at a pressure of 350 torr. After about two hours, the reactor pressure is 875 torr. (a) Has the reaction proceeded to completion at the end of the two-hour period? If not, what percentage of the dimethyl ether has decomposed? (b) Taking elemental species [C(s), H2(g), O2(g)] at 25°C as references, prepare and fill in an inlet-outlet enthalpy table. (See Example 9.5-2.) Use tabulated data for methane, hydrogen, and carbon monoxide, and the following data for dimethyl ether: Δ H f 180.16 kJ mol C p J mol K 26.86 0.1659 T 4.179 10 5 T 2 T in kelvins (c) Calculate Δ H r 600 C and Δ U r 600 C for the dimethyl ether decomposition reaction. (d) How much heat (kJ) was transferred to or from the reactor (state which it is) during the two-hour period of the reaction? (e) Suppose the reaction were instead carried out in an expandable reactor at 600°C at a constant pressure of 350 torr, with the same final percentage decomposition of dimethyl ether. Calculate the final volume of the reactor and the required amount of heat transfer. (Note: These should both be quick calculations.) Explain why the values of Q calculated in Part d and in this part are different, even though the initial conditions and extents of reaction are the same.

A 0.120 M solution of an enantiomerically pure chiral compound D has an observed rotation of 0.24° in a 1-dm sample container. The molar mass of the compound is 140.0 g/mol.

a) what is the specific rotation of D?

b) what is the observed rotation if this solution is mixed with an equal volume that is 0.15 M in L, L is the enantiomer of D?

c) what is the observed rotation if the solution of D is diluted with an equal volume of solvent?

d) what is the specific rotation of D after the diltuion descibed in part (C)?

e) what is the specific rotation of L, the enantiomer of D, after the dilution described in part C?

f) what is the observed rotation of 100 ml of a solution that contains 0.01 mole of D and 0.005 mole of L? Assume a 1 dm path length

3. Cocaine is a weak organic base whose molecular formula is C​17H​ ​21N​ O​4.​ At 15 degrees​C an aqueous solution of cocaine was found to have a pH of 8.53 and an osmotic pressure of 52.7 torr.

   a) What is the molarity of this solution? b)What is kb of cocaine? c)What concentration of NaOH solution would have the same pH as this solution of

The table of diprotic acids below shows how the acidity of the 1st proton is always much higher than the acidity of the second proton.Thus, the pH of the solution is dominated by the equilibrium for the loss of the 1st proton.

What is the pH for a 1.12 M solution of Li2S?

Drops are used as a measure of volume in this lab.  Explain why it is important to beconsistent in the size and counting of the drops.

Methane, a powerful greenhouse gas, is generated via the anaerobic decomposition of solid waste in landfills. Collecting the methane for use as a gaseous fuel rather than allowing it to be released to the atmosphere provides an alternative to natural gas as an energy source and has a beneficial effect on the environment. If a batch of waste with mass M(tonnes) [1 tonne or 1 metric ton = 1000 kg] is deposited in a landfill at t=0, the rate of generation of methane at a later time t is given by the following equation V CH4 (t) = kL o M waste e -kt where: V CH4 (SCM CH 4 /y) = methane generation rate [SCM = m 3 (STP)] K = rate constant (y -1 ), a measure of how fast the waste decomposes L o = landfill gas yield potential [SCM CH 4 /tonne waste] M waste = tonnes of waste deposited at t= 0
a. Explain in your own words the benefits of reducing the release of methane from landfills and using the methane as a fuel instead of natural gas.
b. Starting with the above equation, derive an expression for the mass generation rate of M CH4 (t)[tonnes CH 4 /y]. Without doing any calculations, sketch the shape of a plot of M CH4 vs t from t=0 to t = 3y, and graphically show on the plot the total masses of methane generated in YEARS 1, 2, and 3 (Hint: Remember your calculus.) Then derive an expression for M CH4 (t)(tonnes CH 4 ), the total methane generated from t =0 to an arbitrary time t.
c. A new landfill has a yield potential L o = 100 SCM CH 4 /tonne waste and a rate constant k = 0.04y -1 . At the beginning of its first year, 48,000 tonnes of waste are deposited. Calculate the tonnes of methane generated from this deposit over a three-year period.
d. A junior engineer solving the problem of Part c calculates the methane produced in three years from the 48,000 waste deposit as M CH4 (t=3) = M CH4 (t=0){tonnes CH 4 /y}x 1y + M CH4 (t=1)x1 + M CH4 (t=2)x1 where M CH4 is given by the first expression derived in Part b.
-- -- -- Briefly state what the engineer is assuming about the rate of methane generation
-- -- -- - Calculate the value she would determine and the percentage error in her calculation, and show graphically what the calculated value corresponds to on another sketch of M CH4 vs t.
-- -- - The answer to Part c is 390 tonnes CH 4 . When one of the text authors first did the calculation of M, the result was 210 tonnes CH 4 . The author immediately knew that something had to be wrong in the calculation. Explain her reasoning.
e. The following amounts of waste are deposited in the landfill on January 1 in each of three consecutive years: Waste (tonnes) Year 1 48,000 Year 2 45,000 Year 3 54,000 Calculate the metric tons of methane generated through December 31 of the third year.
f. One way to avoid the environmental hazard of methane generation is to incinerate the waste before it has a chance to decompose. What problems might this alternative process introduce?

How many milliliters of 4.7 M HCl must be added to 3.9 L of 0.11 M K₂HPO₄ to prepare a pH = 7.44 buffer?