Calculate the percent ionization of arsenous acid
(H3AsO3) in solutions of each of the
following concentrations (Ka = 5.1e-10.)
(a) 0.206 M
%
(b) 0.556 M
%
(c) 0.822 M
%
In: Chemistry
Consider a the titration of 0.685 L of 0.773 M ascorbic acid (H2C6H6O6) with 1.76 M NaOH. What is the pH at the second equivalence point of the titration?
In: Chemistry
Determine the pH of each of the following solutions.
(a) 0.637 M hydrosulfuric acid (weak acid with Ka =
9.5e-08).
(b) 0.764 M hypoiodous acid (weak acid with Ka =
2.3e-11).
(c) 0.458 M pyridine (weak base with Kb =
1.7e-09).
In: Chemistry
Consider the following reaction. It is occuring in a closed system and it is currently at equilibrium:
| 2H2O(g) + Heat ↔ 2H2(g) + O2(g) |
Label each of the following statements with is effect on the
reaction
(shift towards products, shift towards reactants or no change) 1.
Removing hydrogen gas.
(shift towards products, shift towards reactants or no change) 2.
Decrease the pressure on the reaction vessel
(shift towards products, shift towards reactants or no change) 3.
Placing the reaction vessel in an ice bath
(shift towards products, shift towards reactants or no change) 4.
Increase the size of the vessel.
(shift towards products, shift towards reactants or no change) 5.
Removing water vapor from the vessel.
In: Chemistry
FIVE CLINICAL CHEMISTRY QUESTIONS:
1. What is the origin of AFP in the amniotic fluid? When do AFP
levels peak in amniotic fluid? In maternal circulation? When should
maternal blood levels be drawn?
2. What other test performed on amniotic fluid may confirm the diagnosis of a NTD? What values (elevated, decreased) will this assay take if a NTD is present?
3. Describe the delta O.D. spectrophotometric test for amniotic fluid bilirubin and discuss the clinical significance of abnormal results. (Include a description of Hemolytic Disease of the Newborn)
4. Briefly describe the changes in lipid composition of amniotic fluid before and during fetal lung maturation.
5. Describe the triple marker screen for Down syndrome and the expected changes from normal values for each in an affected pregnancy.
In: Chemistry
Plot on the same energy diagram having the vacuum as zero:
(A) the absolute electrochemical potentials, under standard conditions, of the following reactions: (i) H+/H2, (ii) O2/H2O (pH = 1). What is the spontaneous direction of reactions (i) and (ii) if reaction (i) occurs by electron exchange with the conduction band while reaction (ii) occurs by electron exchange with the valence band? Under such conditions, which of the two semiconductors can achieve water splitting (2H2O ® 2H2 + O2)?
(B) The position of the band gaps of the compound semiconductors SrTiO3 and Fe2O3
SrTiO3: band gap is 3.2 eV, conduction band edge = -3.8 eV,
valence band edge = -
6.9 eV. Fe2O3: band gap is 2.2 eV, conduction band edge = -4.8 eV,
valence band edge =
-6.9.
In: Chemistry
In: Chemistry
Calculate the ratio of the packing factors for the following cases: 1) simple cubic to face centered cubic. 2) simple cubic to hypothetical face centered body centered cubic crystal (i.e. a face centered cubic with a similar atom placed in the center 3) simple cubic to a simple hexagonal unit cell (hint: think about the hexagonal unit cell that can be made by deforming a simple cube) 4) a simple cubic crystal that has a central impurity atom that fills the interstitial space to a simple cubic crystal that has a central simple cubic structure in the interstitial space.
In: Chemistry
What is the chemical reaction equation when Vermiculite comes in contact with soil?
In: Chemistry
For the peptide below
Thr, Ser, Tyr, Met, Asp, Phe, His, Lys, Trp, Gly, Pro, Arg, Ile, Glu
Calculate overall charge for pH=5 and pH=11 Calculate overall pI
In: Chemistry
the decomposition of amonia is shown below. if kp is 1.5x103 at 400 C, what is the partial pressure of amonia when the partial pressure of H2 is 0.15 atm and N2 is 0.10 atm at equilibrium?
2 NH3(g)<____> N2 (g) + 3 H2 (g)
The correct answer is 4.47x10-4 atm please and thank you
In: Chemistry
Diets that severely restrict carbohydrate intake often result in ketosis for the dieter.
Explain why this occurs by selecting the correct answer.
| A. When carbohydrates are restricted, the body metabolizes fats for energy, resulting in a quantity of acetyl-CoA that can't be metabolized in the citric acid cycle due to the reduced quantity of acetate, which is used in gluconeogenesis, The body, instead, uses ketosis for energy, and ketogenesis results. |
|
B. When carbohydrates are restricted, the body metabolizes fats for energy, resulting in a quantity of acetyl- CoA that can't be metabolized in the citric acid cycle due to the reduced quantity of oxaloacetate, which is used in gluconeogenesis, The body, instead, uses ketogenesis for energy, and ketosis results. |
| C. When carbohydrates are restricted, the body metabolizes proteins for energy, resulting in a quantity of acetyl-SCoA that can't be metabolized in the citric acid cycle due to the reduced quantity of oxaloacetate, which is used in gluconeogenesis, The body, instead, uses ketogenesis for energy, and ketosis results. |
In: Chemistry
When he received the Nobel Prize in chemistry in
1960, Willard Libby gave a lecture about radioactive dating to the
king of Sweden and assembled guests in Stockholm.
a) It was suspected that cosmic rays from space hit the
Earth. What evidence confirmed this hypothesis?
b) What did Libby have to assume to reach the
conclusion that the expected specific radioactivity of living
matter would be 2.0/8.5 disintegrations per second per gram of C?
What evidence was there to confirm his conclusion?
c) Libby concluded that we humans are in steady
state with respect to our own concentrations of carbon-14 while
alive but not after death. How did he justify this
conclusion?
d) On what basis did Libby conclude that humans are
radioactive? What evidence did he collect to test his
conclusion?
And here is the link provided for answering this question: http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1960/libby-lecture.pdf
In: Chemistry
A 100.0 −mL buffer solution is 0.110 M in NH3 and 0.125 M in NH4Br.
A. If the same volume of the buffer were 0.260 M in NH3 and 0.395 M in NH4Br, what mass of HCl could be handled before the pH fell below 9.00?
B. What mass of HCl could this buffer neutralize before the pH fell below 9.00?
In: Chemistry
Why does the primary structure impact all levels of protein structure? What is unique about the peptide bond that directly impacts protein structure? What intermolecular forces stabilize protein structure? Consider protein denaturation, what environmental forces can cause a protein to lose its structure? What types of interactions are they disrupting? Many proteins require chaperones to properly fold. How do chaperones help proteins fold? What potential problems might arise from a misfolded protein? (An example from the text may be useful but is not required.)
In: Chemistry