A solution containing 3.48 mM X (analyte) and 1.67 mM S (internal standard) gave peak areas of 3483 and 10069, respectively, in a chromatographic analysis. Then 1.00 ml of 8.47 mM S was added to 5.00 ml of unknown X, and the mixture was diluted to 10.0 ml. This solution gave peak areas of 5428 and 4431 for X and S, respectively. Answer the following questions and enter your results with numerical values only.

a) Calculate the response factor for the analyte. (keep four significant figures)

b) Find the concentration (mM) of X in the 10.0 ml of mixed solution.

c) Find the concentration (mM) of X in the original unknown.

Consider the titration of a 23.4 −mL sample of 0.125 MRbOH with 0.110 M HCl. Determine each of the following.

Part A) the initial pH

Part B) the volume of added acid required to reach the equivalence point

Part C) the pH at 5.7 mL of added acid

Part D) the pH at the equivalence point

Part E) the pH after adding 6.0 mL of acid beyond the equivalence point

Describe how the solvents worked as the mobile phase of the liquid chromatography experiment. Why was it necessary to use different concentrations of aqueous isopropanol in the step-gradient separation?

A solution prepared by mixing 60.0 mL of 0.220 M AgNO3 and 60.0 mL of 0.220 M TlNO3 was titrated with 0.440 M NaBr in a cell containing a silver indicator electrode and a reference electrode of constant potential 0.175 V. The reference electrode is attached to the positive terminal of the potentiometer, and the silver electrode is attached to the negative terminal. The solubility constant of TlBr is Ksp = 3.6 × 10–6 and the solubility constant of AgBr is Ksp = 5.0 × 10–13.

(c) Calculate the first and second equivalence points of the titration.

(d) What is the cell potential when the following volumes of 0.440 M NaBr have been added? a. 1.0 ml b. 16.0 ml c. 29.0 ml d. 29.9 ml e. 30.3 ml f. 46.0 ml g. 60.0 ml h. 62.0 ml

Nitrous oxide (N2O) is also known as “laughing gas”. Write all of the resonance structures for N2O (one of the N atoms is the central atom). Then,

~ calculate the formal charges on all atoms in each of the resonance structures, and then

~ rank the resonance structures in order of importance for determining the structure of the resonance hybrid, and

~ predict the bond order for each covalent bond in the resonance hybrid.

You have been asked to experimentally determine the Calorie (1 Calorie = 1000 calories) values of various desserts. You realize that a combustion reaction is analogous to the digestive reaction occurring during metabolism and the amount of energy released from combustion will tell us how much nutritional energy we can expect from the food. You then need to apply the principles of calorimetry to measure the energy released by the desserts upon combustion.

After some research, you discover that calorimetry of combustion reactions is performed in an instrument called a bomb calorimeter, which is shown below. The name “bomb” refers to the inner chamber of the calorimeter that can withstand great increases in pressure.

1.What would happen to the coffee cup if you used it for a combustion reaction?

Hint: For automatic grading purposes, limit your answer to one word.

2. While using a coffee cup calorimeter for a combustion reaction, water in the reaction would ___________ ["not matter", "be a problem"] . This is because water ___________ ["would also need to be burned", "would absorb the energy from the reaction"]         .

3.The main ingredient in the desserts you will be studying is sugar or sucrose. Look up the SDS for sucrose. Name one type of fire extinguisher should you have/use if the fire (combustion reaction) gets out of hand?

Hint: For automatic grading purposes, limit your answer to a single type of fire extinguisher. Do not include "fire extinguisher" or anything to that effect in your answer.

What is the pH of a saturated solution of aluminum hydroxide? Al (OH)3 Ksp is 1.8X10^-33

prepartion of biodiesel lab

Describe the role of potassium hydroxide in this reaction?

Calculate the mass of glucose metabolized by a 53.6 kg person in climbing a mountain with an elevation gain of 1610 m . Assume that the work performed in the climb is four times that required to simply lift 53.6 kg by 1610 m .

You are given 2.00 g of a mixture of phenol, aniline, phthalic acid and methyl benzoate. Describe, how you would use an acid-base extraction technique to separate all three compounds by drawing the flowchart. Propose another way of extraction, where different order of extraction is used (e.g., adding the acid first instead of a base)

Please show how to do each step

LAB: Mass Percent

1-Weigh approximately 5 g NaCl on weigh paper and add to a 250 ml Erlenmeyer flask. Record the exact mass here (The mass is 4.85 g )

2-Using a 100 ml graduated cylinder, add 100 ml water to the flask and stir until the solute has dissolved. Calculate the concentration in mass percent of this solution assuming the density of the water is 1 g/ml.

Solution + flask =227.747 g

Flask =81.565 g

3-Transfer 60.0 ml of the NaCl solution using a 100 ml graduated cylinder to a PREVIOUSLY weighed 150 ml beaker. The mass percent of the solution in the beaker is _______________.

The beaker mass is 93.469 g

4-Weigh the beaker with the 60 ml solution sample and record the mass here _153.623 g. Calculate the mass of solution as well as the mass of solute in the beaker.

5-Transfer 40.0 ml of the NaCl solution from the Erlenmeyer flask to a PREVIOUSLY weighed 150 ml beaker. Don’t forget to weigh the beaker before adding the NaCl solution to it. Record the mass of the beaker is 93.495 g. The mass percent of this solution in the beaker is _______________.

6-Weigh the beaker with the solution and record the mass here 133.790 g. Calculate the mass of solution as well as the mass of solute in the beaker.

7-Compare the masses of the solutions and solutes in each beaker (calculated values in numbers 4 and 6) with their respective concentrations.

Using values from Appendix C of your textbook, calculate the value of Ho, So, and Go for each of the following reactions at standard temperature (298 K). Next calculate G if ALL of the GASSES in the reaction have partial pressures of 0.2 atm.

(a) NaOH(s) + CO2(g) NaHCO3(s) Ho = -127.44 kJ/mol

So = -176.02 J/mol-K

Go = -74.96 kJ/mol

If all gasses have partial pressures of 0.2 atm then G = ________ kJ/mol.

(b) 2 Fe(s) + 3 CO2(g) Fe2O3(s) + 3 CO(g)

Ho = ______kJ/mol

So = _______ J/mol-K

Go = ___________kJ/mol

If all gasses have partial pressures of 0.2 atm then G = ___________kJ/mol.

(c) 2 C2H6(g) + O2(g) 2 C2H4(g) + 2 H2O(g)

Ho = ___________ kJ/mol

So = ________ J/mol-K

Go = ___________ kJ/mol

If all gasses have partial pressures of 0.2 atm then G = _________ kJ/mol.

(d) 6 C(graphite) + 6 H2O(l) C6H12O6(s)

Ho = _______ kJ/mol

So =________ J/mol-K

Go =_________ kJ/mol

If all gasses have partial pressures of 0.2 atm then G = __________ kJ/mol.

Why is it better to use a rotovap instead of a hot plate to evaporate ether?

Consider the following data on some weak acids and weak bases:

Use this data to rank the following solutions in order of increasing pH. In other words, select a '1'next to the solution that will have the lowest pH, a '2' next to the solution that will have the next lowest pH, and so on.

Solution pH

0.1 M NaCl

0.1 M C6H5NH3Cl

0.1 M C5H5NHBr

0.1 M NaCN