Chemistry Answers

A buffer solution is prepared by dissolving 1.50 g each of benzoic acid, C7H6O2, and

sodium benzoate, NaC7H5O2, in 150.0 mL of solution. [Ka = 6.3 x 10-5]

a. What is the pH of this buffer solution?

b. Which buffer component must be added, and in what quantity, to change the

buffer pH to 4.00?

c. What quantity of 2.0 M NaOH or 2.0 M HCl must be added to the original buffer to

change the pH to 4.00.

1. Write the electron configuration for iridium using orbital diagram techniques?

2. Using the spdf notation,write the electron configuration of iodine?

3. Which two of these elements would you expect to show the greatest similarity in chemical ang physical properties: B,CA,F,He,Mg,P?

4.A biochemist who is studying the properties of certain sulfur S-containing compounds in the body wonders whether trace amounts of another nonmetallic elements might have similar behavior. To which element should she turn her attention?

(a)F (b)As (c)Se (d)Cr (e)p

5. Chlorine is a halogen. Locate this element in the periodic table.

(A) What is it's symbol?

(B) Period and group where it is located?

(C) What is it's atomic number?

(D) Is it a metal or nonmetal?

Determine the volume of ethyl alcohol required to prepare 250 mL of a 45% by volume solution.

What mass of zinc is needed to react with 23.1 g of phosphoric acid

What mass of water is consumed by the reaction of 9.04 g of carbon dioxide?

How many grams of Cu(OH)2 will precipitate when excess Ba(OH)2 solution is added to 77.0 mL of 0.678 M Cu(NO3)2 solution?

Calculate the concentration of C6H5NH2, H3O+, and OH− in a 0.230 M C6H5NH3Cl solution. (Kb(C6H5NH2)=3.9×10^−10

Calculate the concentration of C6H5NH3+ and Cl− in a 0.230 M C6H5NH3Cl solution.  

Common aspirin is acetylsalicylic acid, which has the structure shown below and a pKa of 3.5. Calculate the pH of a solution in which one normal adult dose of aspirin (650 mg

mg ) is dissolved in 6.0 ounces of water.

Calculate the pH

pH of a solution in which one normal adult dose of aspirin (650 mg

mg ) is dissolved in 6.0 ounces of water.