Calculate the molar solubility of Fe(OH)2 in a buffer solution where the pH has been fixed at the indicated values. Ksp = 7.9 x 10-16.
(a) pH 7.6
_________M
(b) pH 10.2
__________M
(c) pH 12.0
___________M
In: Chemistry
Calculate the pH change when 10. mL of 3.0 M HCl are added to 500. mL of the following
A ) pure water
B) aqueous solution of 3.0g of formic acid
C) aqueous solution of 4.0g potassium formate
D) aqueous solution containing 3.0 g of formic acid and 4.0 g of potassium formate
In: Chemistry
1. Briefly describe how a drying agent works. List the names and chemical formulas for five typical drying agents.
2. Elemental bromine (Br2)reacts with 3-hexene to form 3,4-dibromohexane.
a. Write out the balanced equation for this reaction.
b. If 11.5 g of 3-hexene is reacted with 8.8 g Br2, what is the theoretical yield of 3,4- dibromohexane?
c. If you did the reaction described in (c) and isolated 15.9 g of 3,4- dibromohexane, what is the percent yield for the reaction?
3. How can you tell, visually, when an organic liquid is dry after adding a drying agent?
4. Write out the mechanism for the dehydration of 2-butanol in the presence of sulfuric acid (via an E1 mechanism).
In: Chemistry
A 1L buffer solution is 0.150M in HC7H5O2 and 0.250M in LiC7H5O2. Calculate the pH of the soln after the additon of 100mL of 1.00M HCl. The Ka HC7H5O2 = 6.5x10^-5
In: Chemistry
Hello, this is for my analytical chemistry class. How do you solve the following question: Calculate the solubility of Pb(IO3)2 in a solution of 0.020M Mg(NO3)2 using activities. Assume that since Pb(IO3)2 is only sparingly soluble that it does not contribute to the ionic strength. Please use the extended Debye-Huckel equation. αPb2+ = 450pm αIO3- = 450pm Pb(IO3)2 Ksp = 2.5*10-13
Thank you.
In: Chemistry
Oxalic acid dihydrate is a solid, diprotic acid that can be used in the laboratory as a primary standard. Its formula is H2C2O4
In: Chemistry
1) Carbon dioxide and water combined typically make up 1-3% of our atmosphere, and yet, we are constantly monitoring the atmospheric content of CO2 and H2O. Why? Explain why they vary from hour to hour and why they are such important gases in our atmosphere despite the fact that they are not the top three gases in our atmosphere.
(2) With one exception, the relative concentrations of atmospheric gases do not change with height. Indicate this exception, its concentration patterns, and reasons why this is the case.
(3) The atmosphere is in constant motion. Why? What is the general pattern of airflow? Explain why there is this general pattern of airflow and why atmospheric gases don’t simply flow into outer space.
(4) The composition of the Earth’s atmosphere has changed in the past 200 years. What are/were the major changes in our atmospheric composition?
(5) Name the top ten air pollutants we presently regulate. Is there a common source for these top ten pollutants? If so, what is it? What percentage of our atmospheric gases do these top ten regulated gases make up?
(5) Name the top ten air pollutants we presently regulate. Is there a common source for these top ten pollutants? If so, what is it? What percentage of our atmospheric gases do these top ten regulated gases make up?
(6) Identify the sinks for the following molecules and the transformation of the molecules due to the sink.
Molecule
Sink for molecule
Form of molecule after sink used
SO2
CO2
O3
NO2
(7) Identify two factors that affect the lifetime of pollutants in the atmosphere, and explain how these two factors affect pollutant lifetime. Why should you be aware of it
(8) When fossil fuel is burned, many different types of carbon-based molecules can be emitted. Of all carbon-based emissions, carbon dioxide is the best-case scenario given what will occur to the other carbon-based emissions. Explain why you agree or disagree with the previous statement and the consequence of this fact.
(9) The CAA dealt with both stratospheric and tropospheric ozone issues. Explain what emissions the CAA limited to address these two issues. It would be helpful to fill in the following table:
|
Emissions in CAA which addressed stratospheric ozone issue (10) A colleague comments to you that the ozone hole must be getting worse since we are having so many ozone alert days. How would you gently correct this misconception of your colleague in relating ozone alert days with the ozone hole? |
Emissions in CAA which addressed tropospheric ozone issue |
In: Chemistry
Consider the following gas-phase reaction:
C2H2(g) + 4 Cl2(g) 2 CCl4(g) + H2(g)
Using data from Appendix C of your textbook calculate the temperature, To, at which this reaction will be at equilibrium under standard conditions (Go = 0) and choose whether >Go will increase, decrease, or not change with increasing temperature from the pulldown menu.
To = K, and Go will
---Select---
increase
decrease
not change with increasing temperature.
For each of the temperatures listed below calculate Go for the reaction above, and select from the pulldown menu whether the reaction under standard conditions will be spontaneous, nonspontaneous, or near equilibrium ("near equilibrium" means that T is within 5 K of To).
(a) At T = 1282 K Go = kJ/mol, and the reaction is
---Select---
spontaneous
nonspontaneous
near equilibrium under standard conditions.
(b) At T = 1923 K Go = kJ/mol, and the reaction is
---Select---
spontaneous
nonspontaneous
near equilibrium under standard conditions.
(c) At T = 641 K Go = kJ/mol, and the reaction is
---Select---
spontaneous
nonspontaneous
near equilibrium under standard conditions.
In: Chemistry
A 17.5 g sample of a candy bar is burned in a bomb calorimeter, which has a heat capacity of 9.25 kJ/°C. The temperature increases from 19.7°C to 57.3°C.
What is the fuel value of the candy bar? In kJ/g
How many Calories are in a 77.7 g candy bar? 1 Cal = 4.184 kJ. In Cal
In: Chemistry
|
The first theories to explain the similarities between bacteria and mitochondria or chloroplasts suggested that an early eukaryotic cell actually engulfed but failed to fully digest a free-living prokaryotic cell. Why is such an event unlikely to account for the origin of mitochondria or chloroplasts? |
In: Chemistry
Find accepted values for the density, molar mass, and molar volume (you may need to calculate this from other literature or accepted values) of oleic acid and Avogadro’s number. Then, Write a formula for how you will calculate percent error.
In: Chemistry
What are the concentrations of H3O+ and OH- in each of the following?
a. 1.55 M NaOH
b. 0.15 M Sr(OH)2
c. 0.056 M HClO4
d. 0.47 M HCl
In: Chemistry
Complete and balance the precipitation reactions. Include physical states in your equations.
AgNO3(aq)+NaCl(aq)----->
K3PO4(aq)+MgCl2(aq)------->
In: Chemistry
Alkene metathesis or olefin metathesis includes two alkenes where the double bonds of the alkenes break and the fragments are reformed, however if the alkenes are asymmetrical there is a mixture of products, is there a way to know if one of the products is more favored, or are we going to have to show the formation of both products for all of these reactions?
In: Chemistry
One scale for electronegativity is based on the concept that the electronegativity of any atom is proportional to the ionization energy of the atom minus its electron affinity: electronegativity = k(IE - EA), where k is a proportionality constant.
a) How does this definition explain why the electronegativity of F is greater than that of Cl even though Cl has the greater electron affinity?
b) Why are both ionization energy and electron affinity relevant to the notion of electronegativity?
c) Determine the value of k that would lead to an electronegativity of 4.0 for F under this definition.
d) Use your result from part c to determine the electronegativities of Cl and O using this scale. Do these values follow the trend based on a figure of electronegativity values based on Paulings thermochemical data.
In: Chemistry