A solution of sodium hydroxide was neutralized by sulfuric acid. The volume of sodium hydroxide solution used was 675.0 mL, and the concentration was 0.875 M. Calculate the moles of sulfuric acid that were neutralized (assuming that the reaction goes to completion). Give your answer to three significant figures. 2NaOH (aq) + H2SO4 (aq) ? Na2SO4 (aq) + 2H2O (l

1.You find to your surprise that the reaction of phenol with acetic anhydride and aluminum trichloride gives a mixture of two disubstituted products. Pick the best reason for why.

A.The OH oxygen reacts twice to give the bisester derivative.

B.Ring acylation occurs twice in the ortho-ortho' and ortho-para positions.

C.The first acylation product is in the ortho and para positions which deactivates the ring and causes meta-substitution with the second acetyl group to give ortho-meta and meta-para diacetylphenols.

D.The first reaction is at the oxygen to give phenyl acetate followed by acetylation in the ortho and para positions to give a mixture of products.

2.Compare the reactivity of the oxygen to acetylation with acetic anhydride for phenol versus cyclohexanol by picking the best answer below.

A.Electron donation by the cyclohexane ring increases nucleophilic attack by the oxygen of cyclohexanol versus phenol.

B.Resonance is greater for the phenol acetyl oxonium intermediate than for the cyclohexanol analog.

C.Base catalyzed formation of the phenolate is faster than for cyclohexanol due to resonance stabilization, and the anion formed is more reactive.

D.In fact, they both react at the same rate.

3.EAS reactions involve attack by something seeking:

A.all of the below.

B.electrons, and those are almost always relatively "available" ones in pi-orbitals.

C.a nucleus to bond to, making the reaction also a "nucleophilic" attack.

D.a one-step reaction involving loss of leaving group at the same time the attacking group makes a new bond.

4.All EAS reactions involve a "tetrahedral" or Td intermediate. Which of the following is true of this statement?

A.Can't happen with an aromatic ring carbon which by definition is sp2 or trigonal planar.

B.There is no intermediate in EAS which simple involves attack at electrons.

C.No, the leaving group leaves at the same time the attacking group forms a bond.

D.Almost all do: an sp2 carbon becomes sp3 in the intermediate.

When NO2NO2 is bubbled into water, it is completely converted to HNO3HNO3 and HNO2HNO2:
2NO2(g)+H2O(l)→HNO3(aq)+HNO2(aq)

Part A

Calculate the pHpH in a solution prepared by dissolving 0.0360 molmol of NO2NO2 in 1.45 LL of water. KaKa for HNO2HNO2 is 4.5×10−44.5×10−4.

Express your answer using two decimal places.

Part B

Calculate the concentrations of all species present (H3O+H3O+, OH−OH−, HNO2HNO2, NO−2NO2− and NO−3NO3−) in a solution prepared by dissolving 0.0360 molmol of NO2NO2 in 1.45 LL of water.

Enter your answers numerically separated by commas.

The hypothetical molecular square H4 is in the D4h point group. (a) Use the 4 1s-orbitals on the H’s involved in s-bonding with the metal as a basis for generating a reducible representation to produce the symmetry-adapted molecular orbital combinations of the H4 square. (b) Reduce the representation to its irreducible components. (c) Sketch the resulting symmetry-adapted molecular orbitals and properly label each of them. Use the projection operator method. (d) Sketch the molecular orbital diagram showing the relative energies of the resultant molecular orbitals. The relative energies can be estimated using the number of nodes present in each SALC.

Temperature: 96.8 ^oC                         Concentration of HCl solution: 0.04998 M

I have to find the answers to those with * next to them and unsure how to do those calculations.

How can you apply the knowledge of molecular orbitals to explain bonding between "hybridization" orbitals, especially sp³ ? in words.. thank you!

A beaker with 1.00×102 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 4.70 mL of a 0.300 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740.

Hypoiodous acid, HIO, has an acid dissociation constant of Ka = 2.3 x 10-11 .

a) What is the useful pH range of a buffer prepared from hypoiodous acid and its conjugate base, hypoiodite?

b) Determine the pH of a solution prepared by mixing 25.0 mL of 0.212 M hypoiodous acid with 30.0 mL of 0.126 M NaOH (you may assume that the volumes of the solutions are additive).

c) What mass of HCl(g) can be added to the solution in part (b) before it is no longer a buffer? Ka (HCl) = 4.5x10^-7

a) From the list below, pick an acid, along with its conjugate base, that can be used to make a pH 7.40 buffer.

H3PO4 Ka = 6.9 x 10-3 H2PO4- Ka = 6.4 x 10-8 HPO42- Ka = 4.8 x 10-13

b) If you have 0.100 M solutions of the acid and the conjugate base in the system that you picked and there was 20.0 mL of the base, how many mL of the acid would you need to make this buffer of pH 7.40?

76

What is the total sample size (in grams) for a sample of ethanol (CH₃CH₂OH) which contains 2.51 g of oxygen?

77.

What is the total sample size (in grams) for a sample of sodium nitrite which contains 3.54 g of oxygen?

What is the pH at the equivalence point in the titration of a 22.6 mL sample of a 0.371 M aqueous acetic acid solution with a 0.353 M aqueous barium hydroxide solution?

pH =

If a solution of NaOH has a 20% mass percent of NaOH and a density of 1.22 g/ml, what is the molarity of this solution ?

Draw a schematic diagram for a Perkin Elmer ultraviolet-visible spectrophotometer, clearly and specifically identifying each important part.  

     b. Draw a schematic diagram for a Shimadzu spectro-fluorometer, clearly and specifically identifying each important part.

     c. Compare a PM tube, a PDA, and a thermocouple with respect to two different aspects.

Use your calculated value of Ksp (1.35 x 10^-7) and Kf (1140) to explain why CdC2O4 is dissolved by ammonia.

How would the formation constant for [Cd(NH3)4 +2] be affected (increase, decrease, or no change) if not all of the CdC2O4 precipitate reacted with NH3?

1. Calculate the mean activity coefficient (g_±) for a 2.0 x 10^-3m Na₃PO₄ solution at 25 ºC.
2. Calculate the activity coefficients (g₊ and g_-) of each ion for a 2.0 x 10^-3m Na₃PO₄ solution at 25 ºC AND the value for the mean activity coefficient.

Thanks in advance!!!