please answer the following questions
What is the spin multiplicity of a Cr(III) ion in its ground electronic state, in an octahedral ligand field?
Locate the Tanabe-Sugano diagram for a d3 electron configuration in an octahedral ligand field. How many spin-allowed transitions are there? How many d-d bands do you expect in the UV-vis spectrum of an octahedral Cr(III) complex?
complexes are
tris(2,4-pentanedionato)chromium(III)
tris(ethylenediamine)chromium(III)
hexakis(urea)chromium(III)
In: Chemistry
Experiments show that the solubility of alum in 23 mL of 1.2 M KOH plus 10 mL of 9 M H2SO4 is about 1.0 g at 1.0 °C and 1.7 g at 6.0 °C. Using your measured solution temperature, estimate the amount of alum left in your chilled solution.
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A 24 g ice cube at -76°C is placed in a lake whose temperature is 82°C. Calculate the change in entropy of the cube-lake system as the ice cube comes to thermal equilibrium with the lake. The specific heat of ice is 2220 J/kg·K. (Hint: Will the ice cube affect the temperature of the lake?)
In: Chemistry
A 111.0 mL sample of 0.105 M methylamine (CH3NH2;Kb=3.7×10−4) is titrated with 0.265 M HNO3. Calculate the pH after the addition of each of the following volumes of acid:
22.0 mL
Express the pH to two decimal places.
44.0 mL
Express the pH to two decimal places.
66.0 mL
Express the pH to two decimal places.
In: Chemistry
Imagine that you are in chemistry lab and need to make 1.00 L of a solution with a pH of 2.80. You have in front of you 100 mL of 7.00×10−2 M HCl, 100 mL of 5.00×10−2 M NaOH, and plenty of distilled water. You start to add HCl to a beaker of water when someone asks you a question. When you return to your dilution, you accidentally grab the wrong cylinder and add some NaOH. Once you realize your error, you assess the situation. You have 82.0 mL of HCl and 86.0 mL of NaOH left in their original containers.
Assuming the final solution will be diluted to 1.00 L , how much more HCl should you add to achieve the desired pH?
In: Chemistry
What is the pH of a 0.11 M solution of C6H5OH (Ka = 1.3 x 10^-10)?
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At a certain temperature, the equilibrium constant for the following chemical equation is 3.40. At this temperature, calculate the number of moles of NO2(g) that must be added to 2.53 mol of SO2(g) in order to form 1.10 mol of SO3(g) at equilibrium.
In: Chemistry
An electron, with a mass of 9.11×10−28 g is orbiting the nucleus of a hydrogen atom. A measurement determines the position of the electron to within ±1.63 nm. The velocity of the electron is measured as 6.39×106 m/s. What is the uncertainty in the velocity of the electron?
In: Chemistry
A beaker with 1.30×102 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 5.40 mL of a 0.440 MHCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740.
Express your answer numerically to two decimal places. Use a minus ( ? ) sign if the pH has decreased.
In: Chemistry
Two solutions with the same concentration and the same boiling point, but one has bensene as the solvent and the other has carbon tetrachloride as the solvent. Determine that molal concentration, m (or b), and boiling point, Tb. I have for benzene: normal boiling point; 80.1C, and Kb(C/m); 2.53 For the carbon tetrachloride: normal boiling point; 76.8C and Kb(C/m); 5.03
In: Chemistry
H2O2 + FeSO4
Is there a sign of reduction or oxidation of H2O2? Explain carefully what is happening. Try to explain using half-rxn (There are 4 half-rxn involved when added together give the decomposition reaction (H2O2 > 2H2O + O2 (g)
In: Chemistry
How many grams of solid ammonium bromide should be added to 1.00 L of a 0.223 M ammonia solution to prepare a buffer with a pH of 9.990 ?
In: Chemistry
a. what role does temperature play in the solubility of a compound in a given solvent? what is the ideal situation for recrystallization regarding a chosen solvent and temperature?
b. when purifying a compound by recrystallization, you need to consider the polarity of the solvent. How should the polarity of your chosen solvent compare to the polarity of your product? explain.
In: Chemistry
a. what role does temperature play in the solubility of a compound in a given solvent? what is the ideal situation for recrystallization regarding a chosen solvent and temperature?
b. when purifying a compound by recrystallization, you need to consider the polarity of the solvent. how should the polarity of your chosen solvent compare to the polarity of your product? explain.
In: Chemistry
What is the "octet rule" and what role does it play in Lewis structures. Use the octet rule to predict Lewis structures for a few simple molecules such as ammonia (NH3), carbon dioxide (CO2), ozone (O3), ethane (C2H6), ethylene (C2H4) or acetylene (C2H2).
Please add references
In: Chemistry