mokim06

Approximately 1 in 1000 men have Kleinfelter's Syndrome, a genetic abnormality in which those affected have two X chromosomes and a Y chromosome (XXY). Turner Syndrome, another genetic disorder, results from having a single X chromosome and no Y chromosome. Describe the meiotic events that could lead to the birth of an individual with Kleinfelter's Syndrome. Describe the meiotic events that could lead to the birth of an individual with Turner Syndrome.

What are the five most important musical instruments?

Need question 9 answered please look at the image to answer the question

Figure 36-3

Choose a chromosomal abnormality and provide us some more information on it e.g. Klinefelter syndrome, Down syndrome, Turner syndrome, Triple X syndrome, etc. Please site your research and references.

3.26 Discussion: Observing Mitosis

Describe to your classmates the steps of mitosis that you identified. Explain how you were able to tell one stage from another stage.

A scientist measures the standard enthalpy change for the following reaction to be -215.7 kJ: CO(g) + 3 H2(g)-->CH4(g) + H2O(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(g)

A scientist measures the standard enthalpy change for the following reaction to be -201.9 kJ:

CO(g) + 3 H₂(g) --->CH₄(g) + H₂O(g)

Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CO(g) is kJ/mol.

A scientist measures the standard enthalpy change for the following reaction to be 217.1 kJ : CH4(g) + H2O(g)->3H2(g) + CO(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(g) is _ kJ/mol.

A scientist measures the standard enthalpy change for the following reaction to be -340.2 kJ : 2Na(s) + 2 H2O(l)2NaOH(aq) + H2(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(l) is ____________kJ/mol.

A scientist measures the standard enthalpy change for the following reaction to be -14.1 kJ: 3Fe2O3(s) + H2(g)2Fe3O4(s) + H2O(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(g) is kJ/mol.

b. A scientist measures the standard enthalpy change for the following reaction to be -582.2 kJ : H2CO(g) + O2(g)CO2(g) + H2O(l) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CO2(g) is kJ/mol.

A)
A scientist measures the standard enthalpy change for the following reaction to be -209.6 kJ :
CO(g) + 3 H₂(g)------>CH₄(g) + H₂O(g)
Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CH₄(g) is________ kJ/mol

B)A scientist measures the standard enthalpy change for the following reaction to be -577.3 kJ:
H₂CO(g) + O₂(g)-------->CO₂(g) + H₂O(l)
Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H₂O(l) is __________kJ/mol.

C)
A scientist measures the standard enthalpy change for the following reaction to be -346.4 kJ :
2Na(s) + 2 H₂O(l)------->2NaOH(aq) + H₂(g)
Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H₂O(l) is_________ kJ/mol.

All three problems are a set of one homework problem for my assignment, so please answer all three. Thank you!

A scientist measures the standard enthalpy change for the following reaction to be -736.8 kJ : 2CO(g) + 2 NO(g)2CO2(g) + N2(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CO(g) is ____ kJ/mol.

Q1:

A- A scientist measures the standard enthalpy change for the following reaction to be 71.9 kJ :

2CO₂(g) + 5 H₂(g) ----> C₂H₂(g) + 4 H₂O(g)

Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CO₂(g) is____ kJ/mol.

B- A scientist measures the standard enthalpy change for the following reaction to be -139.1 kJ :

H₂(g) + C₂H₄(g) ----> C₂H₆(g)

Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of C₂H₄(g) is ___kJ/mol.

C- A scientist measures the standard enthalpy change for the following reaction to be -593.4 kJ :

2CO(g) + O₂(g) ----> 2CO₂(g)

Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CO₂(g) is ___kJ/mol.

A scientist measures the standard enthalpy change for the following reaction to be -171.2 kJ:

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

Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of SO2(g) is ? kJ/mol.

A scientist measures the standard enthalpy change for the following reaction to be 6.8 kJ : Fe(s) + 2 HCl(aq)FeCl2(s) + H2(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of HCl(aq) is kJ/mol.

1.

Using standard heats of formation, calculate the standard enthalpy change for the following reaction.

H2(g) + F2(g) 2HF(g)

_______ kJ

2.

Using standard heats of formation, calculate the standard enthalpy change for the following reaction.

NH4Cl(aq) NH3(g) + HCl(aq)

________ kJ

3.

A scientist measures the standard enthalpy change for the following reaction to be -230.2 kJ :

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

Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of SO3(g) is _________kJ/mol.

4.

A scientist measures the standard enthalpy change for the following reaction to be 3.0 kJ :

Fe(s) + 2 HCl(aq) FeCl2(s) + H2(g)

Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of HCl(aq) is _______kJ/mol.

Calculate the standard enthalpy change of reaction (ΔH°) for the following reaction using the reaction enthalpies and the standard enthalpies of formation (ΔHf°) of the reactants and products:

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

Given: ΔHf° (SO2) = -296.8 kJ/mol ΔHf° (O2) = 0 kJ/mol ΔHf° (SO3) = -395.6 kJ/mol

Note: All enthalpy changes are given per mole of substance.

Calculate the number of moles of solute present in 500 mL of a 0.75 M solution of magnesium chloride (MgCl2).

Please provide the balanced reaction equation for this experiment.

Thank you!

Green Chemistry:

Reaction:

1. Obtain a 100 mL beaker. Add a stir bar, 30 mL DI water, and 8 g (13 mmol) Oxone. The 13 mmol refers to the active portion of Oxone. As part of the prelab look up Oxone in Sigma-Aldrich and determine what the active portion is.

2. Place on the center of a magnetic stirrer and stir until the Oxone is completely dissolved in the water. This will take 20-25 minutes. If the solid does not all dissolve, pour the liquid into a clean beaker and assume it is a saturated solution.

3. Add some ice and water to make an ice bath in an evaporation dish and place on the magnetic stirrer. Magnetic stirrers are really designed to have only one flask on them at a time, so you may have to adjust the placement of the two flasks to ensure both are stirring.

4. To a clean (does not have to be completely dry) 100 mL round bottom flask add a stir bar, 30 mL of acetone, 1.482 g of trans-anethole (10 mmol), and 4 g (47.6 mmol) of solid pure NaHCO3. Clamp the round bottom flask to the ringstand, placing the round bottom flask in the ice bath.

5. Begin stirring. When this solution is sufficiently cooled to ≈ 0 °C and the Oxone solution is ready, transfer the Oxone solution to a separatory funnel.

6. Add the Oxone solution dropwise to the round bottom flask containing your alkene. Use caution to avoid causing an overly vigorous reaction.

7. Once the addition of the Oxone solution is complete, remove the flask from the ice bath and stir unheated for 30 minutes. You will see lots of white salts precipitate out of solution. (What are these salts?)

Reaction Workup
1. Attach a separatory funnel holder to the ring stand in the hood. Set a separatory funnel in the ring. Flute or cone a large piece of P8 filter paper and place in a large plastic stemmed funnel (not a Hirsch or Buchner). Pour the reaction mixture through the filter paper into the separatory funnel.

2. Wash the solid with a small 10 mL diethyl ether using a pipette.

3. Add 25 mL diethyl ether to the separatory funnel, shake and vent three times. The aqueous layer will be on the bottom (why?).

4. Drain off the aqueous layer into a beaker.

5. Drain off the organic layer into a 125 mL Erlenmeyer flask. This whole process is called extracting.

6. Put the aqueous layer back in the separatory funnel and extract again with another 25 mL of diethyl ether. Drain off the aqueous layer and add the first organic layer to the second organic layer in the separatory funnel.

7. Add 20 mL DI water to the combined organic layers, shake and vent three times, and let the layers separate. This is called washing.

7. Add 20 mL of saturated aqueous NaCl (brine) to the organic layer. Shake well and vent several times. Let the layers separate. Drain off the aqueous layer.

8. Pour the organic layer into a 125 mL Erlenmeyer flask. Add a small (size of your fingertip) amount of drying agent. We are using anhydrous magnesium sulfate. Stir the solution for 10 minutes to adequately dry the ether.

9. When the ethereal solution is dry (snow globe effect), filter to remove the drying agent. Flute or cone a large piece of P-8 filter paper and place in a stemless or stemmed plain funnel (not a Hirsch or Buchner). Filter into a clean dry pre-weighed (tared) 100 mL round bottom flask.

Compound Price per gram (list)
trans-anethole $1.41
oxone $0.42
sodium bicarbonate $0.12

acetone $0.33
diethyl ether $0.12

sodium chloride $0.13
magnesium sulfate $0.17

Waste disposal (aqueous or organic): $2.50 /lb.

Product is trans-anethole oxide. Actual yield 0.97. Theoretical yield 1.642 g. 59.07% yield

1. Calculate the atom economy calculations for oxone reaction, cost of reaction per g of product (this includes all reagents/starting materials needed to run the reaction and do the workup), g of waste per g of isolated product, cost of waste per g of isolate product

Upon the completion of the Grignard reaction described in your lab handout, you’re left with a solution of the conjugate base of your product, the solvent (diethyl ether), and magnesium salts. You begin the isolation protocol by adding 10% aqueous sulfuric acid, then transferring the mixture to a separatory funnel. Using the flow chart below, determine which layer each of your components partitions into by drawing their structure in the boxes provided.

You have dissolved 2 g of a mixture of benzoic acid and naphthalene in 30 ml of diethyl ether and started the extraction procedure.

Match the question with an appropriate answer from the drop-box. Before answering the questions below get the data about density of the solvents you use.

Bart was a truly superb organic laboratory student. Unfortunately, his partner Homer was a bit careless. Bart was carefully saving solid samples of benzoic acid and ethyl-4-aminobenzoate in his lab locker; he needed to run melting point determinations on these samples after they had dried for a week. Before he got a chance, Homer picked up both samples, dumped them together in a beaker, and was about to carry them to a waste jar. Bart recovered the beaker, and decided he could easily separate the two components. How would Bart best recover the ethyl-4-aminobenzoate from the solid mixture ?

A) Dissolve the solid mixture in ether, extract the ether solution with 10% aqueous sodium hydroxide, collect the aqueous layer and add an acid.

B) Dissolve the solid mixture in ether, extract the ether solution with 10% aqueous hydrochloric acid, collect the aqueous layer and add a base.

C) Dissolve the solid mixture in ether, extract the ether solution with 10% aqueous sodium hydroxide, collect the ether layer and let the ether evaporate.

D) Dissolve the solid mixture in ether, add about the same volume of water, shake, separate and discard the aqueous layer, let the ether layer evaporate and collect the product.

A student performs the following steps to isolate biphenyl from a solid 1:1 mixture of biphenyl and salicylic acid.

Dissolve 2.0 grams of the mixture in 20 mL of ether

Extract the ether layer 2-3 times with an aqueous solution of 5% sodium

bicarbonate

Add 2-3 spatula tips of sodium sulfate to the ether layer

Extract the ether layer with a saturated aqueous solution of sodium chloride.

Isolate the organic layer and evaporate the ether.

The solid they collect at the end weighs 1.23 g and has a wide melting point range. If the student expected to recover 1 gram of pure biphenyl, explain, based on the procedural information given above, why this student did not see their expected results. Hint: The order of steps in an extraction can be important.