1) What is the enthalpy of reaction, ΔHrxn for the reaction of nitrogen gas with oxygen gas to produce NO2(g), based on the following information? These reactions are not at standard state or at 298 K.
N2(g) + O2(g) → 2 NO(g); ΔH =
83.1 kJ
2 NO2(g) → 2 NO(g) + O2(g); ΔH =
-141.7 kJ
Report your answer in kJ to 1 decimal place.
2)What is the value of ΔHrxn if the
reaction below is reversed? In other
words, PCl5 becomes the reactant. Report your
answer in kJ to 1 decimal place.
PCl3(g) + Cl2(g) → PCl5(g);
ΔHrxn = 414.7
In: Chemistry
in the synthesis of tris(ethylenediamine)nickel (II) chloride
dihydrate lab, give me a good introduction in a clear statement of
the problem or project and the reasons for studying it. Please I am
stuck.
In: Chemistry
For 500.0 mL of a buffer solution that is 0.185 molL−1 in C2H5NH2 and 0.175 molL−1 in C2H5NH3Cl, calculate the initial pH and the final pH after adding 0.020 mol of HCl.
In: Chemistry
What is the pH of a 3.4x10-8 M HClO4 solution at room temperature?
A.7.1
B.7.0
C.5.3
D.6.9
In: Chemistry
Solve the following problems. You MUST show your work.
1. Consider the following reaction 2 SO2(g) + O2(g) = 2SO3(g) Write the equilibrium expression, Kp
2. Consider the following reaction 2 H2O(g) + C(s) = H2(g) + CO2(g) Write the equilibrium expression, Kp
In: Chemistry
The AIDS drug zalcitabine (also known as ddC) is a weak base with the structure shown below and a pKb of 9.8
What percentage of the base is protonated in an aqueous zalcitabine solution containing 570 mg/L ?
In: Chemistry
H2SO4 is a strong acid because the first proton ionizes 100%. The Ka of the second proton is 1.1x10-2. What would be the pH of a solution that is 0.100 M H2SO4? Account for the ionization of both protons.
|
A. 0.955 |
|
B. 2.05 |
|
C. 0.963 |
|
D. 1.00 |
In: Chemistry
Calculate the concentration of all species in a 0.135 M solution of H2CO3. Enter your answers numerically separated by commas. Express your answer using two significant figures.
In: Chemistry
A beaker with 105 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 4.30 mL of a 0.400 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740.
In: Chemistry
The solubility product constant for La(IO3)3 is 1.00×10-11 at 25 oC. What is the molar concentration of IO3- ions in a saturated solution of La(IO3)3? Assume an ideal solution at 25 oC.
How many grams of La(IO3)3 (663.6 g/mol) can be dissolved in 500 mL of pure water at 25 oC?
How many grams of La(IO3)3 can be dissolved in 500 mL of a 0.100 M KIO3 solution at 25 oC? Use activities for this calculation. 0.964 is the number you use to find the answer
In: Chemistry
A)Draw the mechanism of bromination of cis-2-butene.
B)Explain the stepwise mechanism of the reaction between mercury (II) acetate to ethylene
C)Explain with suitable examples the concept of E-and Z- alkenes. Is there any difference between Cis/Trans with E/Z ? Justify your answer.
D)Cis-2-Butene has a higher boiling point (4 0C) than trans-2-butene (1 0C) — Explain.
E)How can you correlate the melting points of oleic acid, linoleic acid and linolenic acids with their double bonds?
In: Chemistry
a volume of 75mL of 0.040M NaF is mixed with 25mL of 0.10M Sr(NO3)2. Calculate the concentration of the following ions in the final solution (Ksp for SrF2= 2.0x10^-10). [NO3-] [Na+] [Sr2+] [F-].
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Describe how pseudopellitierene can be separated from compounds that aren't amines by solvent-solvent extractions. Discuss the influence of acid-base chemistry on solubility properties. Answer the question in the procedure.
In: Chemistry
Consider the titration of 35.0 mL of 0.260 M HF with 0.215 MNaOH. Calculate the pH at each of the following points.
Part A.)
How many milliliters of base are required to reach the equivalence point?
Express your answer using three significant figures.
Part B.)
Calculate the pH after the addition of 8.75 mL of base
Express your answer using two decimal places.
Part C.)
Calculate the pH at halfway to the equivalence point.
Express your answer using two decimal places.
Part D.)
Calculate the pH at the equivalence point.
Express your answer using two decimal places.
Part E.)
Calculate the pH after the addition of 70.0 mL of base.
Express your answer using two decimal places.
In: Chemistry
A 0.4423 g sample of pewter, containing tin, lead, copper, and zinc, was dissolved in acid. Tin was precipitated as SnO2·4H2O and removed by filtration. The resulting filtrate and washings were diluted to a total volume of 200.0 mL. A 15.00 mL aliquot of this solution was buffered, and titration of the lead, copper, and zinc in solution required 35.87 mL of 0.001481 M EDTA. Thiosulfate was used to mask the copper in a second 20.00 mL aliquot. Titration of the lead and zinc in this aliquot required 33.95 mL of the EDTA solution. Finally, cyanide was used to mask the copper and the zinc in a third 25.00 mL aliquot. Titration of the lead in this aliquot required 25.03 mL of the EDTA solution. Determine the percent composition by mass of each metal in the pewter sample
In: Chemistry