Questions
what is the pH of a solution that mixes 30.00 mL of 0.010 M Ch3oh with...

what is the pH of a solution that mixes 30.00 mL of 0.010 M Ch3oh with 30.00 mL 0.00750 M Nach3co2?

In: Chemistry

The triple point of ammonia is at 196.2 K and 49.42 torr. The molar enthalpy change...

The triple point of ammonia is at 196.2 K and 49.42 torr. The molar enthalpy change of vaporization is equal to 24.65 kJ mol-1 at this temperature.
a. Find the normal boiling temperature of ammonia.
b. The actual boiling temperature is -33 ̊C. Find the average value of the molar enthalpy change of vaporization for the range between the triple point and the normal boiling temperature.

In: Chemistry

1. Which of the following alkyl halides would not be suitable to make a Wittig reagent...

1. Which of the following alkyl halides would not be suitable to make a Wittig reagent

1-bromo-2-methylpropane

2-bromobutane

2-bromo-2-methylpropane

(Bromomethyl)cyclopentane

In: Chemistry

How does molecular shape and structure give rise to physical properties. (e.g, phase, viscosity, boiling point,...

How does molecular shape and structure give rise to physical properties. (e.g, phase, viscosity, boiling point, etc.) of a bustance.

In: Chemistry

a) What is the pH of a buffer solution prepared by mixing 120 mL of a...

a) What is the pH of a buffer solution prepared by mixing 120 mL of a 0.435 M CH3CO2H with 50 mL of a .286 M CH3CO2Na solution? CH3CO2H Ka = 1.75 x 10-5

b) What is the resulting pH if we add 10.2 mL of a .513 M HCl solution to this buffer? Does the pH make sense? Why/why not?

c) What is the resulting pH if we add 3.56 mL of a 0.420 M NaOH solution to the original buffer?

In: Chemistry

Calculate the pH at 25 C of a 0.75 M aqueous solution of phosphoric acid (H3PO4)....

Calculate the pH at 25 C of a 0.75 M aqueous solution of phosphoric acid (H3PO4). (Ka1, Ka2, and Ka3 for phosphoric acid are 7.5*10-3, 6.25*10-8, and 4.8*10-13, respectively.)

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TLC Experiment Discuss the reason behind different Rf values of dye by considering the chemical structures...

TLC Experiment

Discuss the reason behind different Rf values of dye by considering the chemical structures of dyes,mobile, and stationary phase

Amaranth O- water Rf=0.9555
Amaranth O- ethanol Rf=0.6455
Amaranth O- silica gel (discuss only interactions between them)

In: Chemistry

± Introduction to Solubility and the Solubility Product Constant Learning Goal: To learn how to calculate...

± Introduction to Solubility and the Solubility Product Constant

Learning Goal:

To learn how to calculate the solubility from Kspand vice versa.

Consider the following equilibrium between a solid salt and its dissolved form (ions) in a saturated solution:

CaF2(s)⇌Ca2+(aq)+2F−(aq)

At equilibrium, the ion concentrations remain constant because the rate of dissolution of solid CaF2 equals the rate of the ion crystallization. The equilibrium constant for the dissolution reaction is

Ksp=[Ca2+][F−]2

Ksp is called the solubility product and can be determined experimentally by measuring thesolubility, which is the amount of compound that dissolves per unit volume of saturated solution.

Part A

A saturated solution of lead(II) chloride, PbCl2, was prepared by dissolving solid PbCl2 in water. The concentration of Pb2+ ion in the solution was found to be 1.62×10−2M . Calculate Ksp for PbCl2.

Express your answer numerically.

Ksp =

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Part B

The value of Ksp for silver sulfide, Ag2S, is 8.00×10−51. Calculate the solubility of Ag2S in grams per liter.

Express your answer numerically in grams per liter.

In: Chemistry

1. On page 410 in your Brown & Foote textbook, the following reaction is shown. 3-pentanol...

1. On page 410 in your Brown & Foote textbook, the following reaction is shown.

3-pentanol + HBr --heat--> 3-bromo-pentane (major product) + 4-bromo-pentane (minor product)

a. Explain how the minor product can form in this reaction and what does it tell us about the mechanism by which the reaction proceeded.

b. Is there any basis in reality to the books claim regarding this reaction? Perform a literature search to see if indeed any chemist reported such results. If you do find such a paper, give the full citation of the paper.

2. Part of the procedure this week calls for a reflux which has a water cooled condenser open on the top to the atmosphere. Why would it be a bad idea to stopper or cap the apparatus? Explain what would happen if the apparatus was capped?

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A 1.00 mL ampule of a 0.150 M solution of naphthalene in hexane is excited with...

A 1.00 mL ampule of a 0.150 M solution of naphthalene in hexane is excited with a flash of light. The naphthalene emits 12.5 J of energy at an average wavelength of 349 nm. What percentage of the naphthalene molecules emitted a photon?

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1. Friedel craft alkyation such as methylation of Nitro benzene did not yield any either meta...

1. Friedel craft alkyation such as methylation of Nitro benzene did not yield any either meta or ortho and para products; essentially no reaction occurred. However alkylation of phenol (hydroxybenzene ) gave ortho and para methylphenol. Explain

2. Bromination of aniline gives both ortho and para substituted bromo aniline respectively. However, the nitration of the same aniline gives only a meta-nitroaniline upon nitration. Discuss why.

In: Chemistry

Phosphoric acid is a triprotic acid with the following pKa values: pKa1=2.148 pKa2=7.198 pKa3=12.375 You wish...

Phosphoric acid is a triprotic acid with the following pKa values:

pKa1=2.148 pKa2=7.198 pKa3=12.375

You wish to prepare 1.000 L of a 0.0200 M phosphate buffer at pH 7.720. To do this, you choose to mix the two salt forms involved in the second ionization, NaH2PO4 and Na2HPO4, in a 1.000 L volumetric flask and add water to the mark. What mass of each salt will you add to the mixture?

mass NaH2PO4= ________g mass Na2HPO4= __________g

What other combination of phosphoric acid and/or its salts could be mixed to prepare this buffer? (Check all that apply).

H3PO4 and NaH2PO4

H3PO4 AND Na2HPO4

H3PO4 and Na3PO4

NaH2PO4 and Na3PO4

Na2HPO4 and Na3PO4

In: Chemistry

Answer the following questions: Define the following terms as used in NMR: integration chemical shift magnetic...

Answer the following questions:

  • Define the following terms as used in NMR:
    • integration
    • chemical shift
    • magnetic equivalence
    • splitting (multiplicity)
  • List the properties and all known hazards of deuterated chloroform
  • Why do we use a deuterated solvent instead of regular solvent (CHCl3 vs CDCl3 for example)?

In: Chemistry

Balance the following equation in acidic solution using the lowest possible integers and give the coefficient...

Balance the following equation in acidic solution using the lowest possible integers and give the coefficient of H+. MnO4-(aq) + H2S(g) → Mn2+(aq) + HSO4-(aq)

In: Chemistry

When an optical spectroscopic transition is measured, either by emission or absorption, a so-called lineshape of...

When an optical spectroscopic transition is measured, either by emission or absorption, a so-called lineshape of given intensity and frequency dependence is obtained. For any spectroscopy there exist quantum mechanical or other basic connections to all of the experimental parameters that determine the lineshape. List these experimental parameters and explain how they are related to the previously mentioned connections.

In: Chemistry