A 100.0-mL sample of 0.2 M (CH3)3N (Kb = 5.28 × 10–5) is titrated with 0.2 M HCl. What is the pH at the equivalence point?

What is the pH at the equivalence point of the titration of a strong acid with a strong base?

Calculate the vibrational energy difference, in cm-1, between the v=0 and v=1 energy level in a hydrogen chloride-35 molecule. Isotope masses to three decimal places are taken from NIST and force constants from hyperphysics. Use the isotope mass, not the average mass.

Two structures of alanine can be drawn that have a net charge of zero, but the predominant form of alanine at its pI is zwitterionic. Why is alanine predominantly zwitterionic rather than completely uncharged at its pI? What percent (to one significant figure) of alanine molecules would be in the completely uncharged form at the pI? Hint: pK1 of alanine is 2.35 and pK2 is 9.87.

A) A 29.0 mL sample of 0.274 M methylamine, CH₃NH₂, is titrated with 0.238 M hydroiodic acid.

The pH before the addition of any hydroiodic acid is ______.

B) A 24.5 mL sample of 0.220 M ethylamine, C₂H₅NH₂, is titrated with 0.399 M hydroiodic acid.

At the titration midpoint, the pH is ______.

C) A 28.2 mL sample of 0.293 M dimethylamine, (CH₃)₂NH, is titrated with 0.273 M hydrochloric acid.

After adding 13.6 mL of hydrochloric acid, the pH is ______.  

Calculate the concentration of all species in a 0.150 M solution of H2CO3. H2CO3], [HCO−3], [CO2−3], [H3O+], [OH−] = Enter your answers numerically separated by commas. Express your answer using two significant figures.

Explain precipitate hardening clearly ? Feel free to use a binary phase diagram to illustrate how it is accomplished. Explain how precipitate hardening makes a material stronger and harder ? There are two reasons and only one is pinning of dislocations ?

Please type your answer!!! Thanks

Part A

Calculate the molar solubility of Ni(OH)2 when buffered at pH=8.0.

Express your answer using one significant figure.

Part B

Calculate the molar solubility of Ni(OH)2 when buffered at pH = 10.3.

Express your answer using one significant figure.

Part C

Calculate the molar solubility of Ni(OH)2 when buffered at pH = 12.0.

Express your answer using one significant figure.

At –80°C, K for the reaction N2O4(g) 2NO2(g) is 4.66 × 10–8. We introduce 0.049 mole of N2O4 into a 1.0-L vessel at –80°C and let equilibrium be established. The total pressure in the system at equilibrium will be: (0.78 atm)

In the first 12.0 s of the reaction, 1.6×10−2 mol of O2 is produced in a reaction vessel with a volume of 0.340 L . What is the average rate of the reaction over this time interval?

In the first 12.0 s of the reaction, 1.6×10−2 mol of O2 is produced in a reaction vessel with a volume of 0.340 L . What is the average rate of the reaction over this time interval?

The questions below refer to the following system: Co(H2O)6 2+ + 4 Cl– CoCl4 2– + 6H2O pink blue

When cobalt(II) chloride is added to pure water, the Co2+ ions hydrate.

The hydrated form then reacts with the Cl– ions to set up the equilibrium shown here. 27.) What change will the system undergo if hydrochloric acid is added? (It should become more blue and the equilibrium will shift to the right.)

A mixture containing 15.0 mol% hexane balance N2 flows through a pipe at 6.53 kmol/h. The pressure is 2.00 atm (abs) and the temperature is 100°C. If I want to begin to condense the hexane, what temperature do I need cool to? If I want to condense 80% of the hexane, what temperature do I need to cool to?

Show that the following are eigenfunctions of the Laplacian operator and determine the eigenvalues: a. (r^-1)sinkr

b.( r^-3)[(sin^2)θ]sin2φ

1.A sample of nitrogen at 20.0 °C has a volume of 954 mL at a pressure of 1,101 mmHg. To change the volume to 1,496 mL, what must be the new pressure?

2. A sample of nitrogen has a volume of 4.65 L at 1,639 mmHg and 51 °C. What volume will it occupy at standard temperature and pressure?

3. A sample of O₂ gas with a volume of 6.43 L was collected at 278 °C. What is the volume of the gas if the temperature is changed to 99 °C at constant pressure?