4. A puddle of coastal seawater, caught in a depression formed by some coastal rocks at high tide, begins to evaporate as the tide goes out. If the volume of a puddle decreases to 23% of its original volume, what is the sodium chloride concentration if it was initially 0.449 M?

5. Iron (II) can be precipitated from a slightly basic aqueous solution by bubbling oxygen through the solution, which converts Fe (II) to Fe (III):

                  4 Fe(OH)⁺ (aq) + 4 OH^- (aq) + O₂(aq) + 2H₂O (L) ? 4 Fe(OH)₃ (s)

How many grams of oxygen are needed to precipitate all of the iron in 75 mL of 0.090 M Fe(II)?

Calculate the activity at 25 degrees Celsius of NACl(s) at 1, 10, 100, and 1000 bar. The density of NaCl at 25 degrees Celsius and 1 bar is 2.16 (g/cm3).

If the Ksp of PbI₂ is 7.1 x 10^-9   will precipitation occur when 10 mL of 1.0 x 10^-4 Pb(NO₃)₂ is mixed with 10 mL of 1.0 x 10^-3 M KI? (Show calculation)

Fresh orange juice containing 10 % solids and the balance water is fed to an evaporator to produce final product of concentrated orange juice containing 40% solids. A fraction of the fresh juice bypassed the evaporator to insure fresh taste. The juice that enters the evaporator at 10% is concentrated and leaves the evaporator at 60% solids, and the evaporator product stream is then mixed with the bypassed fresh juice to achieve the desired final concentration of 40 % solids. All percentages are in mass%. Draw and label a flowchart of this process and based on 100 lb/hr of the final 40% mass product. calculate the following flow rates in Lb/hr:

a. Fresh overall feed rate to the process

b. Flow rate of pure water leaving the evaporator and the bypass flow rate

Balance each of the following redox reactions occurring in basic solution.

Express your answer as a chemical equation. Identify all of the phases in your answer.

H2O2(aq)+ClO2(aq)?ClO?2(aq)+O2(g)

Al(s)+MnO?4(aq)?MnO2(s)+Al(OH)?4(aq)

Cl2(g)?Cl?(aq)+ClO?(aq)

In a reaction, aqueous NaOH is titrated against sulfuric acid solution, H2SO4, according to the equation:

2 NaOH (aq) + H2SO4 (aq) --> Na2SO4 (aq) + 2H2O (l)

If 18.62 ml of sulfuric acid are neutralized with 25.00 mL of 0.100 M NaOH, what is its molar concentration (Molarity, M) of sulfuric acid solution?

Hey guys,

So I am doing a presentation on the element Gold, Au. Now I could go look up the information online but I am really running out of time here, could someone provide me with as much information as you can on the elemnt gold(NOTE NOT PLAGIARIZED). Please cite everything and just hook me up with as many paragraphs and information on gold as you can. I will downrate you if you just do a lazy copy paste from google so please be cautius. If this is too much then just ignore this question. BTW even if you can't write paragraphs about gold, try to atleast give me some ideas and questions about the element so that I can answer and finish this powerpoint. THANK YOU!

Explain why the mutation of Asp-52 to Asn-52 decreases enzyme activity of lysozymes by 10,000 fold.

2. Determine the equilibium concentration of each of the reactants and products in Solution B-1 using the table provided below (ICE table). Fill in all blank values

3.Determine the equilibium concentration of each of the reactants and products in Solution B-2 using the table provided below (ICE table). Fill in all blank values

4.Determine the equilibium concentration of each of the reactants and products in Solution B-3 using the table provided below (ICE table). Fill in all blank values

5. Determine the equilibium concentration of each of the reactants and products in Solution B-4 using the table provided below (ICE table). Fill in all blank values

6.Determine the equilibium concentration of each of the reactants and products in Solution B-5 using the table provided below (ICE table). Fill in all blank values

I have no idea how to do problems 2-6. Could someone please help me. Your help is always greatly appreciated! Thank you in advance.

combining selected ion monitoring (SIM) with isotope dilution in electron ionization mass spectrometry allows:

In an experiment similar to this one, the solubility of potassium hydrogen oxalate (KHC2O4, molar mass= 128.13 g mol) is determined. A 5.0 10^-2 M aqueous solution of KCI is saturated with potassium hydrogen oxalate. The following equilibrium results: KHC2O4(s)-----K^+ + HC2O4^-

Following saturation, the solution is filtered. Portions of the filtered saturated solution are titrated with 0.1172M NaOH solution.

The following date are obtained:

Volume of saturated KHC2O4 Solution Titrated, mL Determination #1 25.2 Determination #2 29.1

Volume of NaOH solution used, mL ---------------------Determination #1 36.88 Determination #2 41.81

Temperature of saturated solution, C-------------------- Determination #1 20.1 Determination #2 20.1

Calculate the following:

number of moles off NaOH needed, mol _______________________For both determinations

number of moles of HC2O4 ^- titrated, mol______________________For both determinations

[HC2O4^-] sat. sol'n_______________________________________For both determinations

[K^+]initial______________________________________________For both determinations

[K^+]from dissolved KHC2O4________________________________For both determinations

[K^+] sat. sol'n___________________________________________For both determinations

Ksp___________________________________________________For both determinations

average Ksp

solubility of KHC2O3 in 5.0 x 10^-2M KCI, mol L___________________for both determinations

Average solubility of KHC2O4 in 5.0 x 10^-2 KCI, mol L

solubility of KHC2O4 in 5.0 x 10^-2 M KCI, g per 100 mL

Use the following cell to answer the questions:

Cr / Cr3+ (1.00 M) // Ni2+ (1.00 M) / Ni.

a) How many milligrams of Ni would be plated on the cathode if a current of 0.39 A is drawn for 2.0 hrs?

b) What is [Cr3+] when [Ni2+] has dropped to 10-4 M?

c) What is the cell potential at the conditions described in Part b?

Table of standard reduction potentials: http://www.chemeddl.org/services/moodle/media/QBank/GenChem/Tables/EStandardTable.htm

Nuclear binding energy

Part D

Calculate the mass defect of the helium nucleus 52He. The mass of neutral 52He is given by MHe=5.012225amu.

Express your answer in atomic mass units to four significant figures.

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Part E

Calculate the binding energy E of the helium nucleus 52He (1eV=1.602×10−19J).

Express your answer in millions of electron volts to four significant figures.

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Part F

Calculate the binding energy per nucleon of the helium nucleus 52He.

Express your answer in millions of electron volts to four significant figures.

What is the concentration of hydroxide ions after 50.0 mL of 0.250 M NaOH is added to 120 mL of 0.200 M Na2SO4?

What is the concentration of hydroxide ions after 50.0 mL of 0.250 M NaOH is added to 120 mL of 0.200 M Sr(OH)2?

What is the advantage of using an internal standard in a gas chromatography experiment?