Calculate the mass of methane that must be burned to provide enough heat to convert 347.0 g of water at 18.0°C into steam at 110.0°C.

(Assume that the H₂O produced in the combustion reaction is steam rather than liquid water.)

I don't know to do ii) for letter a, as well as letter d, e and the EC . Can you help?

The combustion of carbon monoxide is represented by the equation below:

CO(g) + ½O 2 (g) → CO 2 (g)

(a) (i) Determine the value of the standard enthalpy change, ΔH o rxn, for the combustion of CO(g) at
298 K using the following information. (3 pts)

C(s) + ½O 2 (g) → CO(g) ΔH o 298 = -110. 5 kJ mol -1
C(s) + O 2 (g) → CO 2 (g) ΔH o 298 = -393.5 kJ mol -1

(ii) Which is larger, the total bond dissociation energy of the reactants or the total bond
dissociation energy of the products? Explain. (2 pts)

(b) Determine the value of the standard entropy change, ΔS o rxn , for the combustion of CO(g) at 298
K using the information in the following table. (3 pts)
Substance S o 298(J mol -1 K -1 )
CO(g) 197.7
CO 2 (g) 213.7
O 2 (g) 205.1

(c) i) Determine the standard free energy change, ΔG o rxn , for the reaction at 298 K. Include units with
your answer. (3 pts)

ii) Is the reaction spontaneous under standard conditions at 298 K? Justify your answer. (2 pts)

(d) Calculate the value of the equilibrium constant, K eq , for the reaction at 298 K. (3 pts)

(e) Assume ∆H o and ∆S o for the reaction are independent of temperature.
(i) Explain why there is a temperature above 298 K at which the algebraic sign of the value of
∆G o changes. (2 pts)

(ii) Theoretically, the best yield of CO 2 should be achieved at low temperatures or high
pressures. Explain each. (hint: apply Le Chatelier’s principle) (2 pts)

EC a) Write a net ionic equation for: Lithium metal is strongly heated in nitrogen gas. (2 pts)

b) Predict the sign of ΔS° for the reaction at 25°C. Justify your prediction. (1 pt)

In the laboratory you dissolve 13.2 g of iron(III) acetate in a volumetric flask and add water to a total volume of 500 mL.

What is the molarity of the solution?  M.

What is the concentration of the iron(III) cation?  M.

What is the concentration of the acetate anion?  M.

identify salts that will dissolve to give an acidic solution:

LiCl

C6H5NH3Cl

NaNo2

CH3NH3Br

CH3COONa

KClO4

Identify salts that will dissolve to give a nuetral soultions:

LiCl

C6H5NH3C

NaNo2

CH3NH3Br

CH3COONa

KClO4

Identify salts that will dissolve to give a basic soultions:

LiCl

C6H5NH3C

NaNo2

CH3NH3Br

CH3COONa

KClO4

1. You are considering two different calcium supplements. One contains 1250 mg of Ca₃(PO₄)₂ and the other is 1500 mg of CaCO₃. As a good chemist you are interested in the percent mass of calcium in each compound, Ca₃(PO₄)₂ versus CaCO₃. Calculate the mass percent of calcium in each compound AND in each supplement serving.

Calculate the percent ionization of arsenous acid (H₃AsO₃) in solutions of each of the following concentrations (K_a = 5.1e-10.)

(a) 0.211 M

%



(b) 0.497 M

%



(c) 0.886 M

%

Calculate the pH during the titration of 25.00 mL of 0.1000 M HF(aq) with 0.1000 M RbOH(aq) after 15 mL of the base have been added. Ka of HF = 7.4 x 10-4.

Please use I.C.E Table and Before/After Reaction Table.

What is the pH of a solution made by mixing 0.514 moles of HBr and 0.299 moles of KOH, where the resulting volume of the solution is 50.0 L?

Consider an anaerobic process where glucose is fermented to succinic acid and ethanol as products (as well as CO2 and H2O), with biomass growth occurring through acetyl-CoA (assume K=5 mol ATP/C-mol biomass). Determine through a structured approach (i.e. DRAFT) the overall stoichiometric reaction.

1) Given the two reactions

1. H2S(aq)⇌HS−(aq)+H+(aq),  H2S(aq)⇌HS−(aq)+H+(aq),   K1K1K_1 = 9.53×10⁻⁸, and
2. HS−(aq)⇌S2−(aq)+H+(aq),  HS−(aq)⇌S2−(aq)+H+(aq),   K2K2K_2 = 1.13×10⁻¹⁹,

what is the equilibrium constant K_final for the following reaction?

S2−(aq)+2H+(aq)⇌H2S(aq)

2) Given the two reactions

3. PbCl2(aq)⇌Pb2+(aq)+2Cl−(aq),  PbCl2(aq)⇌Pb2+(aq)+2Cl−(aq),   K3K3K_3 = 1.80×10⁻¹⁰, and
4. AgCl(aq)⇌Ag+(aq)+Cl−(aq),  AgCl(aq)⇌Ag+(aq)+Cl−(aq),   K4K4K_4 = 1.13×10⁻⁴,

what is the equilibrium constant K_final for the following reaction?

PbCl2(aq)+2Ag+(aq)⇌2AgCl(aq)+Pb2+(aq)

1. Which of the following species is attacked by benzene in the electrophilic nitration reaction? (a)HNO₃ (b)NO₂^- (c)NO₂⁺ (d) NO⁺
2. Which of the following is the strongest activating group in electrophilic aromatic substitution reactions? (a) CH₂CH₃ (b) OCH₃ (c)CO₂CH₃ (d) NO₂
3. In electrophilic aromatic substitution reactions a bromine substituent is (a) a deactivator and a m-director (b) a deactivator and an o,p-director (c) an activator and a m-director (d) an activator and an o,p-director

4. List at least two of the limitations associated with the Friedel-Crafts alkylation reaction

5. Which of the following compounds would most likely be used in the preparation of tertiarybutylbenzene? (a) (CH3)₂CHCOCl (b) (CH₃)₃CCOCl (c)CH₃CH₃CH₃COCl (d) CH₃CH₃COCl

6. Which of the following compounds is least reactive in the nucleophilic aromatic substitution reactions with NaOH? (a)2,4-dinitrochlorobenzene (b)m-nitrochlorobenzene (c)o-nitrochlorobenzene (d)3,5-dinitrochlorobenzene

7. Which mechanism of nucleophilic aromatic substitution reaction proceeds via a benzyne intermediate? (a) addition-elimination mechanism (b)elimination-addition mechanism

8. Which mechanism of nucleophilic aromatic substitution reaction proceeds via a negatively charged Meisenheimer complex? (a) addition-elimination mechanism (b)elimination-addition mechanism

1)How many grams of KH₂PO₄ are needed to prepare 100.0 mL of a 0.100 M buffer with a pH of 7.25 (assume a pKa of 6.86)?

2)How many grams of K₂HPO₄ are needed to prepare 100.0 mL of a 0.100 M buffer with a pH of 6.75 (assume a pKa of 6.86)?

3) Phosphoric acid has three pKa’s (pKa₁, pKa₂, pKa₃), which pKa is most relevant to the buffer in an experiment?

Predict and calculate the effect of concentration changes on an equilibrium system. Some SO2Cl2 is allowed to dissociate into SO2 and Cl2 at 373 K. At equilibrium, [SO2Cl2] = 0.234 M, and [SO2] = [Cl2] = 0.136 M. Additional SO2 is added so that [SO2]new = 0.216 M and the system is allowed to once again reach equilibrium. SO2Cl2(g) SO2(g) + Cl2(g) K = 7.84×10-2 at 373 K (a) In which direction will the reaction proceed to reach equilibrium? (b) What are the new concentrations of reactants and products after the system reaches equilibrium? [SO2Cl2] = M [SO2] = M [Cl2] = M

Question 1

The lines observed in H-lamp are parts of Balmer Series. All these lines are due to a transition from various higher n value to a common n. What is this common lower n value for all these lines?

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Question 2

The bright violet line of Hg lamp has a wavelength of 435.8 nm. What is the energy of the photon associated with this emission line?

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Question 3

Given: In Atomic Spectra lab, a student obtained his best-fit line equation to be y = 0.29 x + 46.8 when he plotted his Vernier reading on the y-axis and wavelength in nm on the x-axis.

Question: If the Vernier reading for a line is 185.4, what is the predicted wavelength of this line in nm? (Keep 4 sig figs with one decimal place.)

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Question 4

The only electron in a hydrogen atom moved from n=2 to n=6. What is the wavelength of photon (in nm) being associated with this transition? Use whole numbers of nm without any decimal places, such as "415", "1125".

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Question 5

Which of the following transitions in a hydrogen atom will absorb the highest amount of energy?

Suppose a 480. mL flask is filled with 0.720 mol of N2 and 1.32 mol of NO. This reaction becomes possible: N2 (g) + O2 (g) ⇌ 2 NO(g)

The equilibrium constant Kc is 7.62 at the reaction temperature.

• Calculate the equilibrium molarity of O2 .

• (Round final answer to two decimal places.)