a) Increasing the flow rate of the mobile phase would
1. increase longitudinal diffusion.
2. increase broadening due to mass transfer.
3. increase broadening due to multiple paths.
b) How many 50 mL extractions will it take to remove 95% of Compound A that is in 20 mL of water, if K = 0.3?
In: Chemistry
A single extraction with 100 mL of CHCl3 extracts or removes 88.5% of the weak acid, HA, from 50 mL of aqueous solution. What is the Distribution coefficient, D, for HA at a pH = 3.00? The Ka for HA is 3.5 x 10-5.
In: Chemistry
Q-2) write down the process of iodine manufacture in detail
?
In: Chemistry
Assign oxidation states to all atoms in each compound. (Enter your answer using the format +1 and -2.)
(a) Na2Cr2O7
Na
Cr
O
(b) PCl3
P
Cl
(c) K2Ni(CN)4 (Ni only)
Ni
(d) C2H2O4
C
H
O
(e) HCl
H
Cl
(f) Fe2O3
Fe
O
(g) NH4Cl
N
H
Cl
(h) N2O4
N
O
(i) CrO3
Cr
O
(j) NaH2PO4
Na
H
P O
In: Chemistry
What are Nucleic acids? Why are they important? What are some of the important functions of nucleic acids? Give a list of some important nucleic acids.
In: Chemistry
The calcium supplements taken by many women are composed primarily of powdered calcium carbonate, CaCO3, which is also the primary compoent of marble.
(a) Briefly expain why CaCO3 would be a good source for a woman suffering from chronic heartburn. Use a net ionic equation.
(b) Marble statues erode when exposed to acidic precipitation. Give a brief chemical explanation for this erosion.
(c) Briefly explain why many people prefer antacids in which Mg(OH)2 is the active ingredient over those that use use CaCO3.
In: Chemistry
1. You dissolve 5.00 g sodium hydrogen oxalate (NaHC2O4 ) in suffircient water to produce a final solution volume of 100.0 mL. Assuming all of the solid dissolves, calculate the pH of this solution.
2. You dissolve 5.00 g of sodium oxalate (Na2C2O4) in sufficient water to produce a final solution volume of 100.0 mL. Assuming all of the solid dissolves, calculate the solution pH of this solution.
3. You dissolve 5.00 g of sodium hydrogen oxalate and 5.00 g sodium oxalate in sufficient water to produce a final solution volume of 250.0 mL. Assuming both solids dissolve completely, calculate the pH of this solution.
4. Calculate the pH of the solution prepared in question #3 after 2.00 mL 1.00 M sodium hydroxide is added to it.
5. You dissolve 5.00 g sodium hydrogen oxalate and 1.00 g sodium hydroxide in sufficient water to produce a final solution volume of 250.0 mL. Assuming both solids dissolve completely, calculate the pH of this solution.
6. Calculate the pH of the solution prepared in question #5 after 2.00 mL 1.00 M hydrochloric acid is added to it.
In: Chemistry
The developing chamber is not covered with plastic wrap during the development of the chromatogram. Will the Dion value for the cation be greater than or less than the actual value as a result of this technique error? Explain.
In: Chemistry
1. An aqueous solution is prepared such that pH = 8.2. Determine the [H+] [OH–], and pOH of this solution. Show work.
2. Below are the relative fraction of species versus pH curves for different acids. Based on these curves, rank the acids (carbonic acid (H2CO3), bicarbonate (HCO3 –), phenol (C6H5OH), hydrofluoric acid (HF)) in order of increasing acid strength. Briefly describe reasoning.
3. According to the list of bases in order of increasing base strength up the page, which side of the acid-base reaction shown below is favored at equilibrium? Briefly explain. HPO4 2– (aq) + HS– (aq) H2PO4 – (aq) + S2– (aq) Base: Strongest OH– S2– PO4 3– HPO4 2– HS– H2PO4 – H2O Weakest
4. Below are the chemical structures of three species labeled A, B, and C. One is an acid, one is a base, and one is neither an acid nor a base when dissolved in water. Assign which one is which and briefly explain assignments.
In: Chemistry
Two water samples were analyzed for their copper content by atomic absorption spectroscopy. After 5 replicate analyses, the first water sample was found to have 12.6± 0.9 mg/L copper. After 6 replicate analyses, the second water sample was found to have 13.1± 0.6 mg/L copper. Is the copper content in these water samples significantly different? Report your answer in a full sentence, including all necessary information to explain how confident you are about your answer.
Answer: Since the calculated t value is less than the tabulated value (95%, 9 degrees of freedom, tcalc = 0.6, ttable = 2.3) , the two copper concentrations are not statistically different to 95% confidence.
Can you show me how he got to that answer?
In: Chemistry
|
(PH2)(PN2)/(PNH3)
Be sure to answer all parts. N2(g) + 3H2(g) ⇌ 2NH3(g) Use a format similar to this: KP = (PH2O)^2/(PO2)(PH2)^2 KP = |
In: Chemistry
Consider the half-reaction below (in an acidic solution).
NO3??(aq) ? NO(g)
Which of the following is needed to balance this half-reaction?
| A) 3e?? are needed on the reactants side. | |
| B) 4H?+ are needed on the reactants side. | |
| C) 2 H2O are needed on the products side. | |
| D) All of these are needed to balance the given reaction. |
In: Chemistry
0.1200 g of potassium dichromate primary standard is dissolved, quantitatively transferred into a 250-mL volumetric flask and diluted to volume. 0.3000 g an unknown iron ore sample was dissolved in hydrochloric acid, treated with stanous chloride and mercury(II) chloride, quantitatively transferred to a 100-mL volumetric flask and diluted to volume. 25.00 mL of the unknown iron(II) solution was pipetted into 500-mL Erlenmyer flask and titrated with the potassium dichromate solution. 28.00 mL of potassium dichromate is required to reach the end point.
Calculate the moles of iron(II) in the original unknown sample.
I've tried:
0.3000g * (1 mol /55.845g) = 0.005372 mol Fe(2)
but it says it's a wrong answer.
In: Chemistry
Provide the structure of the Diels-Alder product that would be formed if maleic anhydride were to react with napthalene:
In: Chemistry
Enantiomers are identical in their physical properties. Explain why we can still see a difference in smell and taste in 5 points or more.
In: Chemistry