Part 1: A 1.07 g sample of caffeine (C8H10N4O2) burns in a constant-volume calorimeter that has a heat capacity of 7.28 kJ/K. The temperature increases from 297.65 K to 301.38 K. Determine the heat (qv) associated with this reaction.
Part 2:Now use the data above to find ΔE for the combustion of one mole of caffeine
In: Chemistry
Air containing 1.6 vol% sulphur dioxide is scrubbed withpure water in a packed column of 1.5 m2 cross sectional area and 3.5 m heightpacked with no.2 plastic Intalox saddles, at a pressure of 1 atm. Total gasflow rate is 0.062 kmol/s, the liquid flow rate is 2.2 kmol/s, and the outlet gassulphur dioxide concentration is y = 0.004. At the column temperature, theequilibrium relationship is given by y = 40x. (a) What is L/Lmin (b) Calculate NOG. (c) Determine HOG. (d) Calculate KGa from the data
In: Chemistry
Uranium hexafluoride (UF6) sublimes from a solid to a gas and boils at a very low temperature of 56.5 oC. UF6 is used in the enrichment process of the production of fuel in nuclear reactions. At 56.5 oC and 1.00 atm, what is the density (in g/L) of UF6? = 13g/l
A 2.4 L sample of gas is placed in a container at 25oC and 2 atm of pressure. If the temperature is raised to 50oC and the volume is changed to 5.6 L, what is the new pressure? P=0.929
A gas is placed in a balloon with a volume of 3.0 L at 35oC and 800 torr. What would be the new volume for the gas if placed under STP? V=2.8L
Please explain them I have the solutions to each but Mess up in the process so please include each step thank you in advance!
In: Chemistry
Identify and explain the different conductivity regimes. Where does ionization dominate? How about Intrinsic behavior?
In: Chemistry
A magnesium electrode in 1 M MgSO4 and an iron electrode in 1 M FeSO4 are in electrical contact forming a galvanic cell. Determine the direction the electrons flow, write the reaction that occurs at the cathode and the reaction that occurs at the anode and finally determine the total emf for the reaction.
In: Chemistry
How much heat is evolved in converting 1.00 mol of steam at 155.0 ∘C to ice at -55.0 ∘C? The heat capacity of steam is 2.01 J/(g⋅∘C) and of ice is 2.09 J/(g⋅∘C).
Express your answer in units of kilojoules Assume the system is at atmospheric pressure.
|Q| = ___________ kJ
In: Chemistry
a) Determine the molar solubility of Fe(OH)3 in pure water. Ksp = 2.79 × 10-39 for Fe(OH)3.
(b) Determine the molar solubility of Fe(OH)3 if the pH of the solution is 8.0.
(c) Determine the molar solubility of Fe(OH)3 if the pH of the solution is 2.0.
In: Chemistry
A and B are for and ideal solution. Pure A has a vapor pressure of 84.3 torr, while pure B has a vapor pressure of 41.2 torr. The mole fraction of A in the liquid phase is equal to 0.32.
a). Calculate PA,PB and Ptotal.
b). If a portion of the gas phase is removed and condensed in a seperate container, what will PA,PB, and Ptotal of the new system be?
In: Chemistry
In a lab, we are required to make a 100ml solution that contain: 54.30mg/L sodium salicylate, 0.020M FeCl3, 0.050 M HCl. I will also need to create a blank solution that contains 0.020 M FeCl3 and 0.050 M HCI. The blank solution is also 100.00 mL. At the end, we are required to get an absorbance at 520 nm. What should I do to prepare the solutions? Please give detailed instructions. Thank you very much!
In: Chemistry
(a) A standard iodine solution was standardized against a 0.4123 g primary standard As4O6 by dissolving the As4O6 in a small amount of NaOH solution, adjusting the pH to 8, and titrating, requiring 40.28 mL iodine solution. What is the concentration of the iodine solution?
As4O6 (s) + 6H2O -> 4H3AsO3
H3AsO3 +I3^- + H2O -> H3AsO4 + 3I^- + 2H^+
(b) The purity of a hydrazine (N2H4) sample is determined by titration with triiodide. A sample of the oily liquid weighting 1.4286 g is dissolved in water and diluted to 1 L in a volumetric flask. A 50.00 mL aliquot is taken with a pipette and titrated with the standard iodube solution in (a), requiring 42.41 mL. What is the percent purity by weight of the hydrazine?
N2H4 + 2I3^- -> N2 + 6I^- +4H^+
In: Chemistry
Assuming standard conditions, and considering the table of standard reduction potentials for half-reactions, given in your text, rank the following species according to their relative strength as reducing agents. For example, the most powerful reducing agent would be given rank "1", and the least "6".
Cd
Mn
H2 (acidic half-cell solution)
Na
Cl-
ClO2-
In: Chemistry
What is necessary for a bond to be considered polar?
What is necessary for a molecule to be polar?
In: Chemistry
Assume that liquid water has a temperature-independent capacity of 75 J mol-1K-1, and that for the transition below no heat is lost to the surroundings and the processes are reversible.
a. Calculate the chnge in entropy when 1 mol of liquid water is cooled from 100C to 50 C.
b. Calculate the change in entropy of the system when 1 mol of liquid water at 100C is brought into contact with 1 mol of liquid water at 0C.
In: Chemistry
Explain in detail the principles, mechanisms, and chemical structural features of electroconductive polymers.
In: Chemistry
When comparing two enzymes against a single substrate it is best to compare which of the following experimentally determined values?
kcat
Km
none of these
Vmax
k2
In: Chemistry