Starting with acetylene develop a synthetic strategy to prepare 2,2,7,7-tetramethyloct-(4E)-ene.  Your answer should include the following.

Stereochemical/regiochemical justification

Mechanistic justification (i.e. where possible show mechanism)

Predict the 1H NMR signals for each step and provide a drawing with values inserted above the appropriate proton.  (Do not predict of consider ions or side-products).

Part A: An acid (HA) dissociates as follows:

HA → H⁺ + A^-

The pH of the 0.25 M solution of HA is 4.64.

What is [A^-]?

Express your answer as a decimal, not an exponent.

Part B:

An acid (HA) dissociates as follows:

HA → H⁺ + A^-

The pH of the 0.88 M solution of HA is 1.91.

What is [HA]?

Express your answer as a decimal, not an exponent.

Part C:

An acid (HA) dissociates as follows:

HA → H⁺ + A^-

The pH of the 0.85 M solution of HA is 1.22.

What is the K_a of HA?

Express your answer as a decimal, not an exponent.

Part D:

A student needs to prepare a buffer solution with a PH of 4.43. Assuming a PKa of 4.70 how many ML of 0.1M B^- would need to be added to 18.0ML of 0.1M HB prepare this buffer?

Part E:

A student needs to prepare a buffer solution with a PH of 5.78. Assuming a PKa of 4.42 how many ML of 0.1M NaOH would need to be added to 18.0ML of 0.1M HB prepare this buffer?

Thank you!

Which of these correctly is identified in terms of increasing 1st ionization energy?

A. C < N < O

B. Ne < P < Mg

C. F < Cl < Br

D. Cs < Na < I

E. Ca < Ba < At

1a. If 20.0 grams of sucrose (C12H22O11) were diluted to 100.0 mL with water, calculate:

- Mass percent

- Molarity

1b. If 42.5 mL of isopropanol (C3H7OH) were added to 95.0 mL of water, calculate:

- Volume percent

- Molarity (the density of isopropanol is 0.786 g/mL)

1c. If 65.7 grams of BaCl2 were dissolved in water, and the total solution volume was 145.0 mL, calculate:

- Molarity of BaCl2

- Molarity of Cl-

1. A 1.189 g sample contains only vitamin C (C6H8O6) and sucralose (C12H19Cl3O8). When the sample is dissolved in water to a total volume of 39.0 mL, the osmotic pressure of the solution is 3.57 atm at 297 K. What is the mass percent of vitamin C and sucralose in the sample?

vitamin C: %

sucralose: %

2. A chemist combined chloroform (CHCl3) and acetone (C3H6O) to create a solution where the mole fraction of chloroform, χchloroform,χchloroform, is 0.187 The densities of chloroform and acetone are 1.48 g/mL and 0.791 g/mL, respectively.

Calculate the molarity of the solution.

molarity: MM

Calculate the molality of the solution.

molality: m

Nature of Science and lab safety What makes one statement or claim science? Along these lines, how do you distinguish a scientific claim from a non-scientific claim, or pseudoscience?

Part A: What mass of silver would plate onto the cathode if a current of 7.7 A flowed through the cell for 64 min ?

t=___ s?

Part B: How much time would it take for 318 mg of copper to be plated at a current of 5.0 A ?

t=___ s?

Part C:What mass of silver would plate onto the cathode if a current of 7.7 A flowed through the cell for 64 min ?

A buffer solution contains 0.444 M NH4Br and 0.365 M NH3 (ammonia). Determine the pH change when 0.084 mol NaOH is added to 1.00 L of the buffer. pH after addition − pH before addition = pH change =

A 12.0M HCl solution has a density of 1.18g/ml. what is the concentration of this solution in the following units?

a) weight percent

b) molality

thank you

Write the balanced NET IONIC equation for the reaction that occurs when nitrous acid and potassium hydroxide are combined.

The extent of this reaction is: .
This reaction is classified as .
A. Strong Acid + Strong Base
B. Weak Acid + Strong Base
C. Strong Acid + Weak Base
D. Weak Acid + Weak Base

A. ... Below 50%
B. ... 50%
C. ... Above 50%
D. ... 100%

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Retry Entire Group

How can the peak area be used to quantitatively analyze a sample using GC?

What is the concentration of hydronium ion, H3O + , in 0.10 M HClO at 25°C?

A. 3.0 × 10−8 M

B. 3.0 × 10−7 M

C. 5.5 × 10−5 M

D. 1.7 × 10−4 M

E. 0.10 M

Define the following concepts and provide an exaple for each: solid-liquid extraction, liquiid-liquid extraction, partition coefficient, miscible solvents, immiscible solvents.

What are two systematic and two random errors present in the experimental procedure?