Calculate the mass of sodium acetate (NaC2H3O2) that must be added to make 100 mL of an acetic acid/acetate buffer at pH = 5.0, given that you will use 5.0 mL of 0.50 M acetic acid.

1. Calculate the concentration of acetic acid after 5.0 mL of 0.50 M acetic acid has been diluted to 100.0 mL.

2. Using the Henderson-Hasselbalch equation, calculate the concentration of NaC2H3O2 need in the buffer.

3. Calculate the mass of NaC2H3O2 needed to make 100.0 mL of solution of the concentration you determined in part 2.

4. If you needed a buffer of pH 5.5, would you require more or fewer grams of NaC2H3O2? Why?

PLEASE HELP ME

11.5 mL of a 0.399 M sodium phosphate solution reacts with 19.9 mL of a 0.192 M lead(II) nitrate solution. What mass of precipitate will form?

List 5 reactions to produce Ethyl Bromide and show the mechanisms

What are some of the challenges to working with proteins rather than small chemical compounds?

Each of the following problems relates to the titration of either potassium hydrogen phthalate (KHP, KHC8H4O4) or citric acid (H3C6H5O7) with potassium hydroxide. Balance each chemical equation and then proceed to the following problems.

__ KHC8H4O4 (s) + __ KOH (aq) → __ K2C8H4O4 (aq) + __ H2O (l)

__ H3C6H5O7 (aq) + __KOH (aq) → __K3C6H5O7 (aq) + __ H2O (l)

A. NaF(aq) and AgNO3(aq). If a solid forms when solutions containing these salts are mixed, write the ionic equation.

B. NaF(aq) and AgNO3(aq). If a solid forms when solutions containing these salts are mixed, write the net ionic equation.

C. K2SO4(aq) and Na2CO3(aq).If a solid forms when solutions containing these salts are mixed, write the ionic equation.

D. K2SO4(aq) and Na2CO3(aq).If a solid forms when solutions containing these salts are mixed, write the net ionic equation.

E. LiNO3(aq) and Na2CO3(aq).If a solid forms when solutions containing these salts are mixed, write the ionic equation.

F. LiNO3(aq) and Na2CO3(aq). If a solid forms when solutions containing these salts are mixed, write the net ionic equation.

G. RbCl(aq) and KOH(aq). If a solid forms when solutions containing these salts are mixed, write the ionic equation.

H. RbCl(aq) and KOH(aq). If a solid forms when solutions containing these salts are mixed, write the net ionic equation.

Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if no solid is formed.

If a = -15 eV and b = -6 eV, which is the shortest conjugated carbon chain molecule capable of absorbing some visible light (and thereby becoming colored)?

I cannot figure out the first question, y=?

Based on the data above and using linear regression, determine the relationship between absorbance (y) and concentration (x).

y = _______ x

What is the concentration of a solution with an absorbance of 0.71 a.u.?

Answer: 0.0156 ppm

For the reaction        A(g) + B(g) + C(g)  " D(g)     the following data were obtained at 25°C.

Which choice gives correct kinetics information for this reaction?   Which choice is closest to the rate constant for this reaction?  Which choice is closest to the missing initial rate for Exp’t 5?

Why are these solved differently? i need an explanation not just a quick answer.

The K_sp of Al(OH)₃ is 1.0 x 10^-33. What is the solubility of Al(OH)₃ in 0.00010 M Al(NO₃)_{3? answer is (7.2x10^-11)}

The K_sp of Al(OH)₃ is 1.0 x 10^-33. What is the solubility of Al(OH)₃ in 0.000010 M NaOH? answer is (1.0x10^-18)

A one-liter bottle of a typical sports drink contains 426 mg of sodium ions, 113 mg of potassium ions, and 53 grams of sugars, and provides 190 calories. If sodium chloride is the source of the sodium ions, potassium hydrogen phosphate (K2HPO4) is the source of the potassium ions, and sucrose (C12H22O11) is the only sugar.

PART A:

Calculate the molarity of sodium chloride in the bottle. (Hint: One mole of sodium ion is contained in one mole of sodium chloride.)

Express your answer to three significant figures.

PART B:

Calculate the molarity of potassium hydrogen phosphate in the bottle. (Hint: Two moles of potassium ions are in one mole of potassium hydrogen phosphate.)

Express your answer to three significant figures.

PART C:

Calculate the molarity of sucrose in the bottle.

Express your answer to two significant figures.

The water used in this experiment is sparged with nitrogen to remove any dissolved oxygen. The proton-coupled reduction of oxygen is shown in the following half reaction:

O2 + 4 H⁺ + 4 e^- = 2 H2O

a.Explain why sparging a solution with N2to remove dissolved oxygen is an equilibrium process.

b.Using the half reaction above, write the balanced equation for the reaction of ascorbic acid with oxygen. Show your work.

c.If you didn’t know whether or not O2is capable of oxidizing ascorbic acid, how would you determine this by consulting data? What data would you consult and what would you look for? (Simply trying the reaction is not an acceptable answer.)

Differentiating Metals and Non-Metals discussion forum

The objectives of this discussion forum revolve around the fundamental concepts of atomic theory, molecular structure and properties, and chemical nomenclature (naming). Your initial post to the forum should be in response to the following:

Explain how you would go about distinguishing a metal from a nonmetal.

Consider including the following talking points in your discussion posts this week:

1. An explanation of the differences between metals and nonmetals including the physical and chemical properties of both.
2. An explanation of the differences between ionic and molecular compounds including the physical and chemical properties of both.
3. Nomenclature of ionic and molecular compounds.

QUESTION 4

1. Calculate the...needed to produce a buffer with a pH of 6.50. (K_a of H₂CO₃ is 4.3*10^–7)

   Directions: Type your answers only. You may scan your paper work and send it to me for partial credit if your answer is not correct.

   Your answer should look something like this: Ratio = (your answer)

2. QUESTION 6

3. The pH at the equivalence point during the titration of some sample of NH₃ by HCl is 5.20. What is the reason that pH at the equivalence point of a titration is not 7.0?

   		The pH at the equivalence point corresponds the excess of moles of HCl added.
   		The pH at the equivalence point corresponds the excess of moles of NH3.
   		The pH at the equivalence point corresponds to the hydrolysis of NH4+.
   		The pH at the equivalence point corresponds to the hydrolysis of Cl–.

4. Some indicator has K_a = to 6.3*10^–9. Its un-ionized form is yellow and its conjugate base is red. What color would a solution have at pH = 6.45?

   		Red
   		Orange
   		Green
   		Yellow

5. The sample of 25.0 mL of 0.0100 M HClO is titrated with 0.0200 M KOH. (a) Find the volume of 0.0200 M KOH needed to reach the equivalence point. (b) Calculate the pH at the equivalence point (K_b of ClO^– is 3.0*10^–7).

   Which one of the following combinations cannot function as a buffer solution?

   6)

   		Na2HPO4 and NaH2PO4
   		NaHS and H2S
   		NaHSO4 and H2SO4
   		KHCO3 and H2CO3
   		NH3 and NH4I

6. b)

   Which of the following combinations would be the best to buffer the pH of a solution at approximately 7?

   		Na2HPO4 and NaH2PO4 (Ka = 6.23*10-8)
   		H3PO4 and NaH2PO4 (Ka = 7.52*10-3)
   		Na3PO4 and Na2HPO4 (Ka = 4.8*10-13)
   		KCN and HCN (Ka = 6.17*10-10)

How do you determine if peaks on an emission and excitation spectra are for Raman scattering or Rayleigh scattering?

please give example and reasoning