Find the pH during titration of 20.00ml of 0.1000 M triethylamine, (CH3CH2)3N (Kb=5.210^-4), with 0.1000M HCL solution after the following additions of titrants a) 10.00mL b) 20.70 mL c) 27.00 mL

calculate the pH for a strong acid + strong base titration in which 5.00 mL of the M(OH)₂ was transferred via pipet to a beaker and HCl was added from the buret.

Concentration of base is 0.0721 M

Concentration of acid is 0.0524 M

Please show work.

Calculate the pH:

a) before any HCl is added

b) after the addition of 4.00 mL HCl

c) after the addition of 9.00 mL HCl

d) 4.00 mL beyond the equivalence point

Problem 5: Find the differential and total cross sections in the first Born approximation for elastic scattering of a particle of mass m, which is initially traveling along the z-axis, from a nonspherical, double-delta potential V (~ r) = V0δ(~ r − aˆ k)+V0δ(~ r+aˆ k), where ˆ k is the unit vector along the z-axis.

A combustion analysis of a 0.44g sample of an unknown compound yields 0.88 g CO2 and 0.36 g H2O. If the sample a molar mass of 132 g/mol, what is the molecular formula of the sample?

7. You are given 2.263 g of a mixture of KClO3 and KCl. When heated, the KClO3 decomposes to KCl and O2, 2 KClO3 (s) → 2 KCl (s) + 3 O2 (g), and 632 mL of O2 is collected over water at 20 °C. The total pressure of the gases in the collection flask is 736 torr. What is the weight percentage of KClO3 in the sample? The formula weight of KClO3 is 122.55 g/mol. The vapor pressure of water at 20 °C is 17.5 torr.

Imagine that you are in chemistry lab and need to make 1.00 L of a solution with a pH of 2.50. You have in front of you

100 mL of 6.00×10−2 M HCl,

100 mL of 5.00×10−2 M NaOH,

and plenty of distilled water.

You start to add HCl to a beaker of water when someone asks you a question. When you return to your dilution, you accidentally grab the wrong cylinder and add some NaOH. Once you realize your error, you assess the situation. You have 82.0 mL of HCland 87.0 mL of NaOH left in their original containers.

Assuming the final solution will be diluted to 1.00 L , how much more HCl should you add to achieve the desired pH?

If acidic H2O2 is mixed with Fe^2+, which reaction occurs: the oxidation of Fe^2+ to Fe^3+ or the reduction of Fe^2+ to Fe? Give the balanced redox reaction for each possibility and explain your reason for selecting the reaction which will occur. Assume standard solution concentrations.

For a) I have:

red: H2O2 + 2H+ + 2e- ---> 2 H2O E=+1.78 V

oxi Fe2+ ----> Fe3+ + e- E=-0.77V

Ecell = 1.01V

I'm stuck on b) but for the explanation I think I understand that the one which is more positive is more thermodynamically favoured, but if I'm wrong on this I'd appreciate a pointer in the right direction.

Suppose you were asked to carry out a crossed-aldol condensation reaction between 4-methylbenzaldehyde and 3,3-dimethylbutanal modelled after an experiment performed with benzaldehyde and acetone, a. what product would you expect to make? Write the equation showing the detailed structures of reactants and products? b. propose a detailed mechanism for this reaction? c. what unwanted by-product might be expected in this experiment? Write the relevant equations with detailed structures? What experimental strategy might you attempt to minimize the formation of this by-product. d. how would your major product react with 2,4-dinitrophenylhydrazine? write an equation to depict the relevant details and describe what is observed visually. e. how would your major product react with molecular bromine in carbon tetrachloride? describe what is observed visually.

Determine the pH during the titration of 35.8 mL of 0.233 M methylamine (CH3NH2 , Kb = 4.2×10-4) by 0.233 M HBr at the following points.

(a) Before the addition of any HBr

(b) After the addition of 13.7 mL of HBr

(c) At the titration midpoint

(d) At the equivalence point

(e) After adding 54.1 mL of HBr

Question 28

MA₂B₂ is a molecule where M is the central atom bonded to 2 atoms of A and 2 atoms of B. The fact that it exists in only one form (no isomers) suggests its geometry is

Select one:

a. octahedral

b. square planar

c. tetrahedral

d. trigonal planar

Question 29

A compound is found to consist of 28.1% sodium, 13.2% boron and 58.7% oxygen. What is its simplest formula?

Select one:

a. NaBO₂

b. NaBO₃

c. Na₂B₄O₇

d. Na₃BO₃

Question 30

What mass of carbon is present in 0.500 mol of phenol (C₆H₅OH)?

Select one:

a. 94 g

b. 47 g

c. 36 g

d. 6 g

Question 31

A 4.000 g sample of an unknown metal, M, was completely burned in excess O₂ to yield 0.02225 mol of the metal oxide, M₂O₃. What is the metal?

Select one:

a. Y

b. Ca

c. Al

d. Sc

Question 32

What is the maximum mass in grams of aluminum chloride that could be obtained from 2.50 mol of barium chloride and excess aluminum sulfate? This is the balanced equation for the reaction: Al₂(SO₄)₃ + 3BaCl₂--> 3BaSO₄ + 2AlCl₃. BaCl₂molar mass is 208.3 g/mol and AlCl₃molar mass is 133.3 g/mol.

Select one:

a. 521 g

b. 334 g

c. 222 g

d. 55.8

Question 33

1.0 x 10^-5 g sample of a compound is known to contain 1.36 x 10¹⁷ molecules. This compound is

Select one:

a. CO₂

b. CH₄

c. NH₃

d. H₂O

The reaction NO2 (g) + NO (g) ⇌ N2O (g) + O2 (g) reached equilibrium at a certain high temperature. Originally, the reaction vessel contained the following initial concentration: [NO2]i = 0.0560 M, [NO]i = 0.294 M, [N2O] = 0.184 M, and [O2] = 0.377 M. The concentration of the NO2, the only colored gas in the mixture, was monitored by following the intensity of the color. At equilibrium, the NO2 concentration had become 0.118 M. What is the value of Kc for this reaction at this temperature?

A beaker with 190 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 8.00 mL of a 0.490 M HClsolution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.

A titration is carried out using 20 mL of 0.500 M Formic Acid (1.8 x 10-4) with 0.500 M NaOH. Calculate the pH after 10.0 mL, 20.0 mL, and 30.0 mL of NaOH have been added.

For the following reaction, 29.8 grams of calcium hydroxide are allowed to react with 24.6 grams of hydrochloric acid. calcium hydroxide (aq) + hydrochloric acid (aq) calcium chloride (aq) + water (l) What is the maximum amount of calcium chloride that can be formed? grams What is the FORMULA for the limiting reagent? What amount of the excess reagent remains after the reaction is complete? grams