Q14. A student carries a reaction that becomes more and more acidic as it proceeds due to the formation of H3O+. The latter is detrimental to her reaction as it lowers the pH. She, therefore, chooses to run the reaction in a solution that will prevent this. Which of the following should she pick?

A. A mixture of 0.5 M NaOH and 0.5 M HCl

B. A mixture of 0.5 M HCl and 0.5 M NaCl

C. A mixture of 0.5 M H2CO3 and 0.5 M NH4Cl

D. A mixture of 0.5 M H2CO3 and 0.5 M NaHCO3

E. None of the above

The correct answer is D, I just want to know the reason why. Thumb up guaranteed if the explanation is adequate.

Acidic solution

In acidic solution, the sulfate ion can be used to react with a number of metal ions. One such reaction is

SO42−(aq)+Sn2+(aq)→H2SO3(aq)+Sn4+(aq)SO42−(aq)+Sn2+(aq)→H2SO3(aq)+Sn4+(aq)

Since this reaction takes place in acidic solution, H2O(l)H2O(l) and H+(aq)H+(aq) will be involved in the reaction. Places for these species are indicated by the blanks in the following restatement of the equation:

SO42−(aq)+Sn2+(aq)+     –––→H2SO3(aq)+Sn4+(aq)+     –––

Question A

What are the coefficients of the reactants and products in the balanced equation above? Remember to include H2O(l)H2O(l) and H+(aq)H+(aq) in the appropriate blanks. Your answer should have six terms.

Enter the equation coefficients in order separated by commas (e.g., 2,2,1,4,4,3). Include coefficients of 1, as required, for grading purposes.

B part

Potassium permanganate, KMnO4KMnO4, is a powerful oxidizing agent. The products of a given redox reaction with the permanganate ion depend on the reaction conditions used. In basic solution, the following equation represents the reaction of this ion with a solution containing sodium fluoride:

MnO4−(aq)+F−(aq)→MnO2(s)+F2(aq)MnO4−(aq)+F−(aq)→MnO2(s)+F2(aq)

Since this reaction takes place in basic solution, H2O(l)H2O(l) and OH−(aq)OH−(aq) will be shown in the reaction. Places for these species are indicated by the blanks in the following restatement of the equation:

MnO4−(aq)+F−(aq)+     –––→MnO2(s)+F2(aq)+     –––

question 2

What are the coefficients of the reactants and products in the balanced equation above? Remember to include H2O(l)H2O(l) and OH−(aq)OH−(aq) in the blanks where appropriate. Your answer should have six terms.

Enter the equation coefficients in order separated by commas (e.g., 2,2,1,4,4,3). Include coefficients of 1, as required, for grading purposes.

Assuming a planar surface, calculate how long it will take to dissolve 1 mm thick layer from the mineral. The dissolution rate is a zeroth-order reaction

Must Show all work

3. A key step in the production of sulfuric acid is the oxidation of SO2(g) to SO3(g):

2SO2(g) + O2(g) ----------> 2SO3(g)

At 298K, G= -141.6kJ; H=-198.4kJ; and S=-187.9J/K

a) Us the date to decide if this reaction is spontaneous at 25deg Cand predict how G will change with increasing T.

b) Assuming DH and DS are constant with increasing T, is the reaction spontaneous at 900deg C?

c) If the reaction reaches the equilibrium , calculate the temp.

Water, sodium hydroxide, and 1,6-hexanediamine are all potential nucleophiles. Yet only 1,6-hexanediamine reacts with the adipoyl chloride. Offer an explanation as to why.

A) A mixture of hydrogen and methane gases, in a 5.00 L flask at 73 °C, contains 0.381 grams of hydrogen and 2.42 grams of methane. The partial pressure of methane in the flask is _____ atm and the total pressure in the flask is ____ atm.

B) A mixture of carbon dioxide and nitrogen gases is maintained in a 9.24 L flask at a pressure of 3.39 atm and a temperature of 66 °C. If the gas mixture contains 23.1 grams of carbon dioxide, the number of grams of nitrogen in the mixture is ____ g.

C) The stopcock connecting a 1.07 L bulb containing neon gas at a pressure of 4.94 atm, and a 5.84 L bulb containing hydrogen gas at a pressure of 4.26atm, is opened and the gases are allowed to mix. Assuming that the temperature remains constant, the final pressure in the system is ____ atm.

500ml of each of 0.200 M NaF and 0.050 M CaCl2 are mixed. Calculate the concentration of Ca^2+ remaining in solution after the precipitation of CaF2 is complete.

Ksp of CaF2 = 3.4x10^-11

A)0.05M

B)0.025M

C)3.4x10^-9M

D)1.7x10^-10M

E)1.4x10^-8M

A groundwater contains 1.2 mg/L of iron as Fe3+.

At what pH will all but 0.002 mg/L of Fe3+ precipitate, if the solid formed is ferric hydroxide?

For each of the following compounds, please provide:

a) The best Lewis dot structure for the compound (include any non-zero formal charges). Draw this structure as a 3 dimensional representation that reflects the electron domain geometry for the compound.

b) The electron domain geometry for the compound. In other words, what would be the geometry if all lone pairs were replaced with atoms?

c) The molecular geometry for the compound. For the starred compounds below, there is more than one possible geometry. In that case, draw all possible geometries and indicate which of the geometries you have drawn is the best one, explaining how you arrived at the answer.

d) The location of any one mirror plane through the compound (if they exist). For example, CO2 has two sets of mirror places, one through the O-C-O axis, and another that bisects the O-C-O axis. Please be specific in your answer.

N₂O SeBr₄[*] ClOF₂+ XeF₃+[*]

SCl₃F₃ [*] I₃+ SCN- H₂SO₄   

Can you draw out the mechanisms of 1-butanol, 2-butanol, and 2-methyl-2-propanol with the HCl ZnCl2 reagent? I need full structures.

What is the pH of the solution obtained when 25.0 mL of 0.065M benzylamine, C7H7NH2, is titrated to the equivalence point with 0.050M HCl? Kb=4.7*10^-10. Part 2: What is the pH at the midpoint?

A buffer solution contains 0.72 mol of hydrosulfuric acid (H2S) and 0.70 mol of sodium hydrogen sulfide (NaHS) in 8.60 L. The Ka of hydrosulfuric acid (H2S) is Ka = 9.5e-08.

(a) What is the pH of this buffer?

pH =

(b) What is the pH of the buffer after the addition of 0.17 mol of NaOH? (assume no volume change)

pH =

(c) What is the pH of the original buffer after the addition of 0.53 mol of HI? (assume no volume change)

pH =