One of the substances (ethylene glycol) appeared to increase in temperature as it evaporated (Change in temperature upon complete evaporation: +1.4). How can this be the case? What alteration to the experiment could have been done to test and see if this evaporation could be exothermic or did that liquid even evaporate at all?

What is the pH of a 0.445 M ammonia solution? Express your answer numerically to two decimal places.

Consider the reaction of NH3 with water:
NH₃ + H2O ↔ NH₄⁺+ OH^-
(Kb=Kw/Ka)

and also
NH₄+ H2O ↔ NH₃ + H3O⁺ (Ka = 5.70×10-10)

Including the ICE Tables:

a) Find the pH of 50.00 mL of 0.200M NH3 after the addition of 45.00 mL of 0.200M HCl.

b) Find the pH of 50.00 mL of 0.200M NH3 after the addition of 50.00 mL of 0.200M HCl.

c) Find the pH of 50.00 mL of 0.200M NH3 after the addition of 55.00 mL of 0.200M HCl.  

Benzoic acid is a weak acid that has antimicrobial properties. Its sodium salt, sodium benzoate, is a preservative found in foods, medications, and personal hygiene products. Benzoic acid ionizes in water:

C6H5COOH⇌C6H5COO−+H+

The pKa of this reaction is 4.2. In a 0.57 M solution of benzoic acid, what percentage of the molecules are ionized?

Express your answer to two significant figures and include the appropriate units.

25.0 mL of a 0.0450 M butylamine solution is extracted with 105 mL of solvent. The partition coefficient for the reaction is 2.00 and the pKa of the protonated form of butylamine is 10.640. Calculate the concentration of butylamine remaining in the aqueous phase at pH = 9.80 and pH = 12.1.

Isolation and characterization of the enzyme alkaline phosphate from escherichia coli: protein purification.

2) why is it necessary to dialyze the enzyme after ammonium sulfate precipitation?

Why are aryl and vinyl beta eliminations rare.

A 14.585 g sample of CaCl2 was added to 12.283 g of K2CO3 and mixed in water. A 3.573 g yield of CaCO3 was obtained.

(1) What is the limiting reagent?

(2) Calculate the percent yield of CaCO3.

What spin functions are allowed for the inner pair of electrons (1s²) in the 1s²2s configuration of L_i? What spin functions are allowed for the outer electron (2s) in the same configuration?

In HNMR,

- What are non-equivalent hydrogens

- What are the "# of Hydrogens per Peak"

- What is coupling and chemical shifts?

find the radius of each stable isotope

lead- 204

lead-206

lead-207

lead-208

using the nuclear theory the average radius of a nucleus is given by

R=1.2x10^-13 A^1/3 cm

B) what is the natural % abundance for each isotope above

C) what are the weighted R(cm)

D) what is the total weighted R(cm)

E) what is the weightes average R(cm)

F) relative comparison ration =

Explain what characteristics of functional groups make an organic compound lipophilic and what ones make a compound hydrophilic. Explain why these characteristics are lipophilic or hydrophilic.

What is a lachrymator?

What are appropriate precautions and safety equipment to use when working with lachrymators?

Suppose 5.25 mol of each reactant are used for the following chemical reactions, identify the limiting reactant. Explain.
____ C6H6 (l) + ____ O2 (s) → _____CO2 (g) + _____ H2O (g)

_____ Al (s) + + ____ Cl2 (s) → _____AlCl3 (s)

____ H2S (g) + ____ O2 (s) → _____SO2 (g) + _____ H2O (l)