For the reaction
Ti(s)+2F2(g)→TiF4(s)
compute the theoretical yield of the product (in grams) for each of the following initial amounts of reactants.
A) 4.0 g Ti, 4.0 g F2
B) 2.2 g Ti, 1.7 g F2
C) 0.240 g Ti, 0.278 g F2
In: Chemistry
4. Omit the questions on p. 10-3 of the 262 lab
manual. Answer the following questions instead.
a) A research paper describes that a photochemical reaction takes
place in a quartz vessel but not in a Pyrex vessel. Rationalize
this observation.
b) Why does the benzopinacol precipitate from the reaction mixture
even though it is a diol?
c) What is the purpose of washing with 95% ethanol?
d) The acid-catalyzed rearrangement of benzopinacol to
benzopinacolone is irreversible. Explain.
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A saturated, aqueous solution of a salt having the formula, AX3, is prepared. The equilibrium that is established is: AX3(s) <------> A3+(aq)+3X-(aq). At equilibrium, the concentration of X- is found to be 2.74x10-7 M.
What is the solubility product constant, Ksp, for AX3?
What is the solubility of this compound in a solution that is 1.529x10-2 M NaX (assume that NaX is a completely soluble compound).
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What is the theory behind GC and IR analysis?
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4. A pharmaceutical company plans to use a liquid-liquid extraction to purify a drug that is a weak monoprotic base. The chemical has a pKb = 9.52 at 25oC. The KD for the neutral form of this chemical is 210 when using water and chloroform at 25oC.
a. What fraction of this drug will be extracted from a 15.0 mL aqueous sample into 10.0 mL of chloroform at pH = 9.00 and 25oC?
b. What fraction of this drug will be back extracted at 25oC from the 10.0 mL of chloroform and into a fresh 50.0 mL portion of water that is buffered at pH = 2.00?
c. What overall fraction of the drug will be isolated from the original sample and placed into the final 50.0 mL portion of water under these conditions?
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Interpret the major absorption bands in the infrared spectrum of benzil.
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| Ethylene glycol (EG), CH2(OH)CH2(OH), is
a common automobile antifreeze. It is water soluble and fairly
nonvolatile
(b.p. 197°C). Calculate the boiling point and freezing point of a solution containing475.5 g of ethylene glycol in 3503 g water. The molar mass of ethylene glycol is 62.07 g/mol.
|
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Calculate the pCo2+ after 13.00 mL of 0.03846 M EDTA in the titration of 25.00 mL of 0.020 M Co2+ (Kf = 2.04 x 1016) at pH = 6.00.
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In paper chromotography, what form are the metals ( Zn2+, Co2+, Cu2+, Cd2+ , Fe3+, and Ni2+) ions likely to exist in the moving phase (water/hydrochloric acid/acetone) and what groups in the structure of the stationary phase (cellulose) are interacting with the moving ions in solution?
Note: Filter paper (Whatman #1) serves as the stationary phase, and the mobile phase consists of a mixture of acetone and 6 M hydrochloric acid. A single spot of the mixture to be analyzed is applied near one edge of a sheet of filter paper. A spot of solution containing each of the cations that might be in the unknown mixture is also placed near the edge of the same sheet for comparison. The treated strip is then placed in a covered jar or beaker (which acts as a developing chamber) containing a shallow layer of the solvent mixture (see Figure 3). Since filter paper is very permeable to the solvent, the solvent begins to rise up the strip by capillary action. The various spots on the developed chromatogram will be highlighted by treatment with several chemical reagents to enhance their color. The reagents to be used are ammonia, dimethylglyoxime (DMG), and 8–hydroxyquinoline (oxine).
In: Chemistry
Calculate the percent ionization of formic acid (HCO2H) in a solution that is 0.139 M in formic acid. The Ka of formic acid is 1.77
In: Chemistry
|
Dissociation Constant For the dissociation reaction of a weak acid in water,HA(aq)+H2O(l)?H3O+(aq)+A?(aq) the equilibrium constant is the acid-dissociation constant, Ka, and takes the formKa=[H3O+][A?][HA] Weak bases accept a proton from water to give the conjugate acid and OH? ions:B(aq)+H2O(l)?BH+(aq)+OH?(aq) The equilibrium constant Kb is called the base-dissociation constant and can be found by the formulaKb=[BH+][OH?][B] When solving equilibrium-based expression, it is often helpful to keep track of changing concentrations is through what is often called an I.C.E table, where I. stands for Initial Concentration, C. stands for Change, and E. stands for Equilibrium Concentration. To create such a table, write the reaction across the top creating the columns, and the rows I.C.E on the left-hand side. Initial (M)Change (M)Equilibrium (M)A+ B?AB |
Part A Aspirin (acetylsalicylic acid, C9H8O4) is a weak monoprotic acid. To determine its acid-dissociation constant, a student dissolved 2.00 g of aspirin in 0.600 L of water and measured the pH. What was the Ka value calculated by the student if the pH of the solution was 2.62? Express your answer numerically using two significant figures.
SubmitHintsMy AnswersGive UpReview Part Part B A 0.100 M solution of ethylamine (C2H5NH2) has a pH of 11.87. Calculate the Kb for ethylamine. Express your answer numerically using two significant figures.
|
In: Chemistry
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Write the equilibrium equations, identify the equilibrium variables such as x +/- y, and calculate the pH of a 0.600 liter solution made up as 1.14 M diprotic base B(aq). Kb1=6.87x10^-6; Kb2=7.15x10^-8
In: Chemistry
Under what circumstances can ?G be negative if ?G'
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Hey yall, Im working on a quiz I completed. I really need to get
a 100 I worked all the problems out and i was wondering if one of
yall would mind checking it for me. If i missed one if yall could
tell me how to get the correct answer?
1.The intermolecular forces present in CH3NH2 include which of the
following?
I. dipole-dipole
II. ion-dipole
III. dispersion
IV. hydrogen bonding
ANS: I, III, and IV
2. A liquid boils when its
ANS: vapor pressure is equal to, or greater than, the
external pressure pushing on it.
- I was actually torn between picking this answer choice and "vapor
pressure is exactly one atm"...is that wrong?
3. How much energy (heat) is required to convert 52.0 g of ice at
–10.0°C to steam at 100°C?
| specific heat of ice: | 2.09 J/g·°C | ΔHfus = 6.02 kJ/mol |
| specific heat of water: | 4.18 J/g·°C | ΔHvap = 40.7 kJ/mol |
| specific heat of steam: | 1.84 J/g·°C |
ANS:157.8
kJ
4. Which of the following
liquids would have the highest viscosity at 25°C?
| CH3Br |
| C2H5OH |
| CH2Cl2 |
| ANS : HOCH2CH2OH |
| CH3OCH3 |
5. Which of the following would be
expected to have the lowest vapor
pressure at room temperature?
| ANS: water, bp = 100°C |
| acetone, bp = 56°C |
| ethanol, bp = 78°C |
| methanol, bp = 65°C |
6. Given the following liquids and
their boiling points, which has the highest vapor pressure at its normal boiling
point?
| ANS: | The vapor pressure of each of the liquids at its normal boiling point would be the same. |
| ethanol, bp = 78°C |
| benzene, bp = 80°C |
| water, bp = 100°C |
|
methanol, bp = 65°C |
7. Which of the following liquids
would make a good solvent for iodine, I2?
| ANS: CS2 |
| CH3OH |
| HCl |
| H2O |
| NH3 |
8. What is the boiling point of a
solution of 11.0 g of lactose (C12H22O11) in 145.0g of water? (Kb
(H2O) = 0.52 °C/m)
ANS: 100.1 deg C
9. Calculate the molality of a 20.0% by mass
ammonium sulfate (NH4)2SO4 solution. The density of the solution is
1.117 g/mL.
ANS: 1.89
10. A solution that is 33.6 % by mass of phenol (C6H5OH) in water
is prepared. What is the mole fraction of the phenol?
ANS: 0.0883
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