what is the theory behind acid-base separations (i.e. how does it work and how can it be used to purify an impure organic compound)?

Suppose that a student collects the following spectrophotometric data to determine the relative concentrations of HMR and MR in solution: The abosorbance at 425 nm was measured to be 0.170 and at 520 nm was 0.690, the slopes corresponding to standard Beer's Law plots were as follows:

αIA = 0.072

αIB = 0.306

αIIA = 0.760

αIIB = 0.036

Using this data, calculate the ratio between the relative concentrations of MR- and HMR in this solution.

There is a total of 6 trials for an experiment involving the measurement of standard enthalpies (kcal/mol).

a) If additional data points are taken but the standard deviation and mean remain unchanged, what will happen to the 95% confidence interval? Would it increase, decrease, or stay the same?

b) What are the different ways to identify a systematic error in her data for this experiment ?

Hi, i'm working on lab report on iodometric determination of Cu in Brass and can someone please explain in WORDS on how the analyte (copper) reaction with iodide works? thanks

2Cu2+ + excess I- → 2CuI(s) + I2

A mineral contains 11.11% Ni (58.71 g/mol); 0.300 g of the same is treated and its ammoniacal solution is treated with 50.00 mL of a solution of 0.0911 M KCN. A little KI is added as an indicator and the solution is titrated with 0.0903 M AgNO₃ until slight turbidity appears. What volume of AgNO₃ will be needed?

I need name of the final compound, and step by step equations of the reaction for the experiment below. Ethylenediamine complexes of Cobalt Procedure 1. Dissolved 1.5 g CoCl2 in 5mL water 2. While the CoCl2 6H2O is dissolving, measure out 10mL of an ethylenediamine solution. (The solution is prepared by dissolving 130mL of anhydrous ehylenediamine in one liter of water) 3.Cool the ethylenediamine solution in ice. 4.Slowly add 2.1mL 3M HCl 5.Add the CoCl2 solution to the partially neutrolized ethylenediamine and then slowly add 2mL of 30% H2O2 with stirring 6.Stir until effervescence ceases. 7.Place the mixture on a hot plate and allow to boil gently 8.When the cobalt solution is evaporated the a volume of 6 to 10mL, add and equal volume of concd. HCl and twice the amount of ethyl alcohol. 9.Cool, filter, press dry on the sintered glass funnel. Thanks.

Which amino acidand artificialsweetener areverydangerous to some people? Why?

(Hint: Name and describethe disorder, it symptomology, and maintenance)

The final volume of buffer solution must be 100.00 mL and the final concentration of the weak acid must be 0.100 M.

Based on this information, what mass of solid conjugate base should the student weigh out to make the buffer solution with a pH=7.0 (in grams)? Based on this information, what volume of acid should the student measure to make the 0.100 M buffer solution (in mL)?

My weak acid is Sodium dihydrogen phosphate monohydrate, Ka= 6.23X10^-8, 2.00M and my conjugate base is Disodium hydrogen phosphate heptahydrate, Na2HPO₄*7H₂O

1) Pyridine is a weak base that is used in the manufacture of pesticides and plastic resins. It is also a component of cigarette smoke. Pyridine ionizes in water as follows: C5H5N+H2O⇌C5H5NH++OH− The pKb of pyridine is 8.75. What is the pH of a 0.310 M solution of pyridine? Express the pH numerically to two decimal places

2)Benzoic acid is a weak acid that has antimicrobial properties. Its sodium salt, sodium benzoate, is a preservative found in foods, medications, and personal hygiene products. Benzoic acid ionizes in water: C6H5COOH⇌C6H5COO−+H+ The pKa of this reaction is 4.2. In a 0.61 M solution of benzoic acid, what percentage of the molecules are ionized? Express your answer to two significant figures and include the appropriate units.

. The four substances HCl, I2, HI, and Cl2, are mixed in a reaction vessel and allowed to reach equilibrium in the reaction: 2 HCl (g) + I2 (s) ⇌ 2 HI (g) + Cl2 (g) Certain changes (specified in the first column in the following table) are then made to this mixture. Considering each change separately, state the effect (increase, decrease, no change) that the change has on the original equilibrium value of the quantity in the second column (or K, if that is specified). The temperature and volume are constant. Change Quantity Effect add HCl amount of HI add I2 amount of Cl2 remove HI amount of Cl2 remove Cl2 amount of HCl add HCl K remove HCl amount of I2 add I2 K

Explain the differences between gel electrophoresis and column chromatography. Address the principles behind each separation. Why do large molecules migrate more easily in one method and with more difficulty in the other? Which method generated the most precise results?

Describe and explain observed conductivity changes during the titration of your amino acid. Which parameter is more helpful in locating the first and the second equivalence points, the pH or the electrical conductivity? The amino acid is glutamic acid (HGlu) Thank you.

Ammonia is produced by the catalytic reaction of nitrogen and hydrogen.

A)   Write the chemical reaction and balance it. Determine the stoichiometric coefficients.

B)    If 15 mol/sec of H₂ is fed to the reactor, determine the amount of N₂ required if a 20.% excess (of N₂) is desired.

C)    If 5.0 mol/sec of H₂ exits the catalytic reactor, determine:

i)   ξ.

ii)   the number of moles of all three components exiting the reactor.

iii)   the conversion of H₂ and N₂.

iv)   the exiting concentration of H₂, N₂, and ammonia.

D)   What are strategies to increase the conversion of H₂?

What is the coefficient of H+(aq) after balancing the following equation? Bi3+(aq) + Fe3+(aq) + H2O => BiO31- + Fe2+ + H+(aq)