How many grams of dry NH4Cl need to be added to 2.10 L of a 0.400 M solution of ammonia, NH3, to prepare a buffer solution that has a pH of 8.58? Kb for ammonia is 1.8×10−5. Express your answer with the appropriate units.

acid-catalyzed ester hydrolysis yields the organic acid whereas base-mediated ester hydrolysis yields corresponding salt of the organic acid. explain

Calculate the concentrations of all species in a 0.600 M Na2SO3 (sodium sulfite) solution. The ionization constants for sulfurous acid are Ka1 = 1.4× 10–2 and Ka2 = 6.3× 10–8.

[HSO3^-]=?
[H2SO3]=?
[OH^-]=?
[H^+]

What are ways you can determine the amount of a substance that is unknown? Concentration, depth, volume and density? Just formulas like M= D/V ect... Please give an example and explain for 5 star rating.

Q1: List three variables you could change to improve the effectiveness of the fractional distillation to separating the ethanol from water?

Q2: Why is 200 proof ethanol not food grade while 190 proof one is?

Phosphorus exists as several allotropes that have varying properties. The enthalpy of transition from white P to red P, ΔtransH, is -18 kJ/mol. The densities of white and red phosphorus are 1.823 and 2.270 g/cm3, respectively. At what temperature does white phosphorus become the stable phase at 625 atm of pressure? Assume the formula for phosphorus is P4.

which of the following atoms has the largest ionization energy? O, Li, N, Be or K

Make a flow chart for the synthesis of Benzoic Acid from phenyl magnesium bromide and carbon dioxide. Using your knowledge of the physical properties of the solvents, reactants, and products, show how the products can be purified. Indicate which layer should contain the product in the liquid/liquid extraction steps.

Do the following problem by hand using TI30Xa calculator. Do the problem on a fresh sheet of paper (college ruled, printer paper or engineering paper). Find the decrease in pressure expected in an NFL football if it was inflated in a room at 80oF, left in the room for a while, and brought to field at 40oF, and left there for a while. Use the ideal gas law to find the decrease in pressure as a number in psi. The ideal gas law is given by
pv = RT where p is the pressure, v is the specific volume, R is the universal gas constant, and
T is the absolute temperature. If any numbers for variables are needed, go to your favorite internet source or books. You should seek the least numbers needed
**NOTE: Assume specific volume remains constant. If this is the case how will you solve the problem? What formulas you will use?

Find the pH during the titration of 20.00 mL of 0.1590 M nitrous acid, HNO2 (Ka = 7.1 ✕ 10-4), with 0.1590 M NaOH solution after the following additions of titrant. (a) 0 mL (b) 10.00 mL (c) 15.00 mL (d) 19.00 mL (e) 19.95 mL (f) 20.00 mL (g) 20.05 mL (h) 25.00 mL

The leaves of the rhubarb plant contain high concentration of diprotic oxalic acid (HOOCCOOH) and must be removed before the stems are used to make the rhubarb pie. If pKa1=1.23 and pKa2=4.19, what is the pH of a 0.0330 M solution of oxalic acid?

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.