You are quantitating benzene using isopropyl-benzene as an internal standard. During the first run, you add 100.0 microliters of 500. microgram/mL benzene and 100.0 microliters of 500. microgram/mL isopropylbenzene to a vial and dilute to 1.000mL to prepare a solution that has a final concentration of 50.0 micrograms/mL of benzene and isopropylbenzene. The peak area measured by GC-MS corresponds to 1225 and 1775, respectively.

Taking an unknown sample of a solution containing benzene with a volume of 100.0 microliters, you spike it with 100.0 microliters of 500. microgram/microliter solution of isopropylbenzene and dilute to the 1.000 mL mark. You measure a peak area of 1550 for benzene and 1800 for isopropyl benzene.

The information is organized in the table below with the appropriate dilution factors applied for what is in the sample vial.

What is the concentration of Benzene in the unknown sample, in units of micrograms/mL?

A series of volumetric flasks are being prepared for the analysis of mercury in the drinking water supply using the method of standard addition. To prepare the flasks, 10 mL of drinking water and a varying amount of standard are added to each flask, and the flasks are brought to the 25.00mL mark on the volumetric flask.

The concentration of mercury standard used was 20.0 microgram/mL.

Please use the data tabulated below to provide the concentration of mercury in the drinking water, in units of micrograms/mL.

It is recommended to use Excel or similar software

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A student reaceted 50.0 ml of 1.05 N sodium hydroxide with 50.0 ml of 1.00 N sulfuric acid in a coffee cup calorimeter. From the temperature vs time plot, the average Ti was 25.7 celsius and the Tf of the reaction mixture was 31.2 Celsius. (ignore calorimeter constant).

What is the enthalpy of neutralization?

Predict the sign of the entropy change for each of the following processes and give your reasoning why:

1. Solid sugar is added to water to form a solution.

2. Iodine vapor condenses on a cold surface to form crystals.

3. N₂(g) + 3H₂(g) 2 NH₃(g)

4. H₂O(l) H₂O(g)

5. CaCO₃(s) CaO(s) + CO₂(g)

6. NH₄NO₃(s) + H₂O(l) NH₄⁺(aq) + NO₃^-(aq)

Please let me know why for each questions

Calculate Δ G ∘ rxn for the following reaction: 4CO(g)+2N O 2 (g)→4C O 2 (g)+ N 2 (g) . Use the following reactions and given Δ G ∘ rxn values: 2NO(g)+ O 2 (g)→2N O 2 (g) , Δ G ∘ rxn = - 72.6 kJ 2CO(g)+ O 2 (g)→2C O 2 (g) , Δ G ∘ rxn = - 514.4 kJ 1 2 O 2 (g)+ 1 2 N 2 (g)→NO(g) , Δ G ∘ rxn = 87.6 kJ Express your answer using one decimal place. Δ G ∘ rxn = nothing kJ 2) Consider the following reaction:
CO(g)+2H2(g)⇌CH3OH(g)
Kp=2.26×104 at 25 ∘C. Calculate ΔGrxn for the reaction at 25 ∘C under each of the following conditions.​   

Part A

standard conditions

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Part B

at equilibrium

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Part C

PCH3OH= 1.1 atm ;
PCO=PH2= 1.5×10⁻² atm

Express your answer using two significant figures.

3)

Calculate the pH of a 0.0760 M anilinium chloride solution. A list of ionization constants can be found here.

Calculate the concentrations of the conjugate acid and base at equilibrium. The conjugate acid and conjugate base are represented as HA and A–, respectively.

2. Calculate the theoretical yield (g) of Zyban hydrochloride

3. Write out the mechanism for the a-bromination of 1 (m-chloropropiophenone).

4. Step 2 is a substitution of bromine by t-butylamine. What type of substitution is occurring: SN1 or SN2 Explain based on the reaction’s substrate and solvent.

5. The reaction mixture from the substitution step 2 is extracted with diethylether to isolate the product. State layer (organic or aqueous) in which each of the following compounds will be present in the highest concentration. a. NMP___________________ b. Excess t-butylamine__________________ c. HBr______________________ d. Zyban free base (compound 3a____________________

6. Why are the ether extracts combined then extracted with water at the end of Step 2?

7. The HCl solution used in the final step was made by mixing 20 mL concentrated HCl (12.0 M) with 100 mL isopropyl alcohol. Why wasn’t an aqueous HCL solution used for this part of the synthesis?

8. Describe the pharmacology of Zyban.

Determine the volume (in mL) of 0.411 M hydrochloric acid (HCl) that must be added to 448 mL of 0.914 M sodium butanoate (NaC3H7COO) to yield a pH of 5.48. Assume the 5% approximation is valid and report your answer to 3 significant figures. A table of pKa values can be found here. pKa=4.82

For the following reaction, 10.1 grams of propane (C3H8) are allowed to react with 20.6 grams of oxygen gas . propane (C3H8)(g) + oxygen(g) carbon dioxide(g) + water(g) What is the maximum amount of carbon dioxide that can be formed? _ grams

What is the FORMULA for the limiting reagent?

What amount of the excess reagent remains after the reaction is complete? _ grams

You have an unknown dye solution whose concentration seems to lie between 0.0006M stock solution and a 0.0004 stock solution. Therefore, you had planned to dilute the 0.0006M stock to create your calibration standards. However, you see that there is no 0.0006M stock left but there is plenty of they 0.0004M stock

a. How could you raise the concentration of some of the 0.0004M stock to make 75mL of a 0.0006M solution without adding any more dye? Be sure to show calculations and indicate that volume of 0.0004M required.

b. Please draw a molecular view picture illustrating the moles of dye remaining constant during this process

A 25.0 mL sample of a 0.3400 M solution of aqueous trimethylamine is titrated with a 0.4250 M solution of HCl. Calculate the pH of the solution after 10.0, 20.0, and 30.0 mL of acid have been added; pKb of (CH3)3N = 4.19 at 25°C.

The 9 species are to be separated based on their differences in volatility, primarily using distillation columns.(benzene,p-xylene, toluene, ethylene, cumene, hydrogen, methane , ethane, propane , propyl) rank the species from most volatile (#1) to least volatile (#9), and what is the physical properties used to make this determination.

Which of the following statements is true?

Fast reactions have small rate constants.

Slow reactions have large rate constants.

A rate equation contains concentration terms for all reactants involved in a one-step mechanism.

A rate equation contains concentration terms for all the reactants involved in a multi-step reaction.

calculate the thermodynamic favorability of aerobic Mn(II) oxidation and aerobic Fe(II) oxidation at pH 2 and 7? Would an organism grow from these processes?

Show all work and don't use previous answers similar to this because they aren't correct. Thanks.

. During the preparation of your dish(chocolate pudding, pasta, bread), the chemical composition of each ingredient plays a role in the texture, aroma and appearance of the final product. Use the table below to describe the chemical composition (molecules, elements, ions, etc.) for the basket ingredients and its corresponding chemical changes and/or physical changes occurring while cooking.