In a titration of 40.55 mL of 0.3137 M nitrous acid with 0.3137 M aqueous sodium hydroxide, what is the pH of the solution when 40.55 mL of the base have been added?

Calculate the pH during the titration of 20.00 mL of 0.1000 M C6H5OH(aq) with 0.1000 M NaOH(aq) after 19.9 mL of the base have been added. Ka of phenol = 1.0 x 10-10.

3a. If the molar absorptivity constant for the red dye solution is 5.56×104 M-1 cm-1 , calculate the molarity of the red dye solution with absorption = 0.900. You may assume L = 1.22cm. Hint: A=εLC

b. Convert the molarity in part a to w/v%. Show your work. Molar mass of FD&C red #3 = 879.86g/mol w/v% is defined as weight (in grams) of solute/100 mL of solution You should remember that w/v% always refers to the grams of materials in 100mL of solution. ppm is defined as mg of solute/ L of solution (1mg = 10-3 g) ppb is defined as µg of solute / L of solution (1µg = 10-6 g)

c. If you want to dilute the red dye solution in part a by 5 times in a single dilution step, explain in two sentences on how one should proceed with the dilution. In addition, what is the final concentration of the diluted solution? Show your work for the numerical part of this question. You are only allowed to use a 5-mL volumetric pipet, a 10-mL volumetric pipet, a 50-mL volumetric flask and/or a 100-mL volumetric flask during the dilution. You may NOT reuse the same pipet during the dilution.

(b) Which have a molecular dipole moment? (Select all that apply.)

CF₄

BF₃

PF₃

OF₂

F₂

Experimental Organic Chemistry 1

HPLC Questions

- What's the difference between single point calibrations and five point calibrations?

- How could you improve your resolution on a chromatograph?

- What's the difference between isocratic runs and gradient runs?

Contrast the reaction to form biodiesel with the reaction to form soap. Why do they form different products given that both reactions start out with a base and a fat or oil?

Use Slater's Rules to calculate Z* for

A. 3p electron in the element P

B. 4s electron in Co

C. 3d electron in Mn

Part A MX (Ksp = 3.97×10−36)

S = _____ M

Part B Ag2CrO4 (Ksp = 1.12×10−12) Express your answer in moles per liter.

S = _____ M

Part C Ni(OH)2 (Ksp = 5.48×10−16) Express your answer in moles per liter.

S = _____ M

A 19.57 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 223 g of water. The freezing point of the solution was measured as -3.85 °C. Calculate the mass percent of sugar in the mixture. A list of Kf values can be found here.

Experimental Organic Chemistry 1

-How do you know when you should use GC or HPLC?

-What's the difference between Reverse Phase HPLC and Normal Phase HPLC?

10) . Use the principles that you learned in Part ii to calculate the standard reduction potentials for each half-cell, given that the E° for Cu2+ + 2e-  Cu (s) is 0.34 V.Note that E° for a half-reaction is not dependent on the coefficients, provided of course that the reaction is balanced, i.e., E° for Ag+ + e- Ag (s) is the same as E° for Ag+ + 2e- 2 Ag (s)

Refers to Procedures Part III Step 9

* Pb results are most unreliable

Define the followings.
(a) collision flux
(b) Stokes law
(c) Fick's second law
(d) Einstein-Smoluchowski equation
(e) half-life of a first-order reaction
(f) Forster theory of resonance energy transfer
(g) Mechaelis-Menten mechanism

Consider the titration of 40.0 mL of 0.200 M HClO4 by 0.100 M KOH. Calculate the pH of the resulting solution after the following volumes of KOH have been added. a. 0.0 mL d. 80.0 mL b. 10.0 mL e. 100.0 mL c. 40.0 mL

answers are A) 0.699 B) 0.854 C) 1.301 D) 7.00 E) 12.15 I would just like to know how to do the work please and tbank you

A bottle filled with 0.5 L of an aqueous solution is at equilibrium with the gas containing 70 % (mole fraction) of nitrogen, N2, and 30 % of oxygen, O2. The temperature is 25 oC and the total pressure of the gas is 10 atm. The Henry’s Law constants for nitrogen and for oxygen in the solution are 6.1 × 10-4 mol L-1 atm-1 and 1.3 × 10-3 mol L-1 atm-1 .

(i) Calculate the partial pressure of oxygen and of nitrogen in the gas.

(ii) Calculate the molarity of nitrogen and oxygen dissolved in the solution.

(iii) Calculate the mass of nitrogen and the mass of oxygen released from the solution when the pressure in the gas was decreased to 1 atm at temperature 25 oC.

(iv) Calculate the volume of the gas released from the solution at pressure 1 atm and temperature 25 oC.

Iron reacts with chlorine gas according to the following balanced chemical equation:

2Fe(s)+3Cl2(g)→2FeCl3(s)

A) What mass of iron(III) chloride is produced when 101.08 g iron reacts with 185.42 g chlorine gas?

B) What is the percent yield of iron(III) chloride if 139.13 g of iron(III) chloride is actually obtained?