#1. Estimate ΔH for the reaction using bond dissociation energies. Give your answer in kcal. C6H12O6 has five C−C bonds, seven C−H bonds, seven C−O bonds, and five O−H bonds.

#2. Is the reaction exothermic or endothermic?

#3. The following equation shows the conversion of aluminum oxide (from the ore bauxite) to aluminum:
2Al2O3(s)→4Al(s)+3O2(g),  
ΔH = +801.0 kcal

----> a. Is the reaction exothermic or endothermic?

Consider the titration of a weak base (B- ) with a strong acid (HCl). Draw (this can be hand drawn) a pH (not pOH) vs mL HCl graph (it will not look the same as the one in question #13; if you start with a weak base, will the pH be low or high? As H+ is added, will the pH increase or decrease?). Label the titration curve with letters A-E, and describe the relative quantities of the dissociated base (B- ) and its conjugate acid (HB), H+ and OHat each point throughout the titration (before the ½ equivalence point [A], at the ½ equivalence point [B], after the ½ equivalence point but before the equivalence point [C], at the equivalence point [D], and after the equivalence point [E]). Locate the position where pH = pKb on your graph.

A layer of peat beneath the glacial sediments of the last ice age had a carbon-14 content of 25 % of that found in living organisms. How long ago was this ice age?

Express your answer using four significant figures

Constant boiling HCl has a concentration of 11.6 M. Your laboratory assistant is going to dilute this acid for you to create a stock solution of HCl for you to use in this experiment. What volume of the 11.6 M HCl must the assistant add to one liter volumetric flask so that the concentration of the stock solution will be 0.62 M after dilution to the mark the water?

What is the pH of this stock solution?

You will now use this 0.62 M HCl solution to carry out a series of dilutions, measuring the pH of each diluted sample. Calculate the [Cl^-] and [H+] concentrations and the pH of each sample.

Sample A will be produced bby pipetting 1.00 mL of the stock solution into a 25 mL volumetric, and diluting to the volume with distilled water.

[Cl^-]=

[H+]=

pH=

Sample B will be produced by pipetting 1.00 mL of sample A into a 25 mL volumetric, and diluting to volume with distilled water.

[Cl^-]=

[H+]=

pH=

Sample C will be produced by pipetting 1.00 mL of sample B into a 25 mL volumetric, and diluting to volume with distilled water.

[Cl^-]=

[H+]=

pH=

Sample D will be produced by pipetting 1.00 mL of sample C into a 25 mL volumetric, and diluting to volume with distilled water

[Cl^-]=

[H+]=

pH=

Sample E will be produced by pipetting 1.00 mL of sample D into a 25 mL volumetric, and diluting to volume with distilled water

[Cl^-]=

[H+]=

pH=

Sample F will be produced by pipetting 1.00 mL of sample E into a 25 mL volumetric, and diluting to volume with distilled water

[Cl^-]=

[H+]=

pH=

Different manufacturers claim to have the best antacid. Which of the following tablets would neutralize the most acid for the money?

A. Rolaids (550 mg CaCO3 and 110 mg Mg(OH)2 per tablet) – 150 tablets for $9.44

B. Tums (500 mg CaCO3 per tablet) – 150 tablets for $5.49

C. Phillips (1200 mg Mg(OH)2 per 15 mL) – 769 mL for $9.99

Show all work to get full credit and circle your final answer. You may need to write balanced chemical equations…

What are the three basic types of solids and the composite units of each? What types of forces hold each type of solid together?

Air. Write in reasonable detail, using the macroscopic nature (our experience) and microscopic nature (molecular level) the composition of air, pollutants in air, where pollutants come from, how they impact health and environment, and what steps are being taken to keep air clean. Share your thoughts on this topic.

At 25 C, you conduct a titration of 15.00 mL of a 0.0400 M AgNO3 solution with a 0.0200 M NaI solution within the following cell:

Saturated Calomel Electrode || Titration Solution | Ag (s)

For the cell as written, what is the voltage after the addition of the following volume of NaI solution? The reduction potential for the saturated calomel electrode is E = 0.241 V. The standard reduction potential for the reaction

Ag⁺ + e^- --> Ag(s)

is E0 = 0.79993 V. The solubility constant of AgI is Ksp = 8.3 x 10^-17.

.600 mL = ______ V

10.30 mL= ______ V

30.00 mL= ______V

38.80 mL= ______V

i keep getting 1 wrong.. its says the total V is hcl and water added together but i did it and its not right. thanks

1. You add Hydrochloric Acid to distilled water. If all the HCl dissociates in solution, calculate the pH of the final solution given the following data. (assume the liquid volumes are addative)
Volume of distilled water used 27.81 mL
Volume of HCl added 1.44 mL
Concentration of added HCl 1.848 M

pH of diluted HCl solution ___________________

2. You weigh a sample of a monoprotic unknown acid and dissolve it in 50.00 mL of distilled water. Exactly half of this solution is titrated with Sodium Hydroxide to the phenolphthalein end point.
The pH of the other half of the original solution is measured with a pH meter. The "neutralized" solution is added to the "original" solution and the pH of this combined "final" solution is also measured.
The following are the measured values:
Mass of unknown acid 1.8105 g
Volume of NaOH used in titration 13.80 mL
Concentration of the NaOH used 0.2213 M
pH of the original acid solution 2.13
pH of the final acid solution 3.24

      CALCULATE the following
(a) Molecular Weight of Acid used in titration ___________________

(b) Molarity of UNKNOWN Acid solution from titration ___________________

(c) Ka of UNKNOWN Acid ___________________

(d) Concentration of undissociated Acid from pH measurements ___________________

(e) Total concentration of UNKNOWN acid from pH measurements ___________________

Why can Hydrogen and helium only hold two electrons in there valence shell, but Neon can hold 8?(You will receive extra credit if you can explain this with quantum numbers)

What is the half-life (T1/2) of a radioactive element with the following conditions?

-Initial Activity = 1000 milliCuries

-Final Activity = 400 milliCuries

-Elapsed Time= 20.0 days

Please show how you got the answers so that I can learn how to do this!

200.00mL of 2.00 M solution of a weak acid is mixed with 300.00 mL of a 2.00 M solution containing its conjugate base. 50.000 g of the slightly soluble salt silver acetate (AgC2H3O2) is added to this buffer solution. After thorough mixing, the solution is assumed to be saturated. To determine the amount of the solid which remains undissolved, the solution is filtered, and the residue is collected and dried; the mass of the undissolved solid is 30.369 g.

a)Based on this information, Calculate Ksp' for silver acetate in this buffer. (*Note Ksp PRIME is needed, not just regular Ksp)

b)Using your value for Ksp', determine the pH of the buffer solution.

c)Based on the pH of the buffer solution, identify the weak acid used to produce it.

A solution is made containing 48.7g of methanol (CH3OH) in 433.3g of water (H2O). What is the mole fraction of water? What is the mass percent of methanol? What is the molality of methanol?

Acodofocation of sodium bicarbonate(NaHCO₃) produces carbon dioxide in a two-step process. The first step produces carbonic acid (H₂CO₃). Write and balance the molecular equation for the first step of the reaction of sodium bicarbonate with HF.

The second step is the decompostion of a carbonic acid to ccarbon dioxide. Write and balance the molecular equation for the second step.

Now write the overall net ionic equation for te acidification of NaHCO₃ to produce CO₂.

What is the molar ratio of CO₂ produced to NaHCO₃ decomposed?

What mass of CO₂ will be produced by the complete decompostion of 1346 mg of NaHCO₃?

Three bulbs are connected by tubing, and the tubing is evacuated. The volume of the tubing is 40.0 mL. The first bulb has a volume of 72.0 mL and contains 6.00 atm of argon, the second bulb has a volume of 250 mL and contains 2.42 atm of neon, and the third bulb has a volume of 21.0 mL and contains 9.88 atm of hydrogen. If the stopcocks (valves) that isolate all three bulbs are opened, what is the final pressure of the whole system in atm?