Hello! We just had a lab where we took measurements of a water-ethanol mix with a densitometer and got volume of ethanol/(total volume of ethanol and water together) and I am stuck on how to convert that to mole fraction of ethanol? Thank you so much!

2 NOCl(g) <=> 2 NO(g) + Cl2(g), K= 1.6E-5. Calculate the concentrations when:

a). 6.0 mol of NO and 2.0 mol of Cl2 in a 1.2-L flask

b).  2.2 mol of NOCl, 2.2 mol of NO, and 1.1 mol of Cl₂ in a 1.0-L flask

c).  1.01 mol/L concentration of all three gases

Please show work and don't just solve the top problem. I need all three and I don't know how to correctly solve either of them!!

Which of the following reactions have a positive ?Srxn? Check all that apply.

2A(g) + 2B(g) -->5C(g)

2A(g) +3 B(s) --> 4C(g)

A(s) + 2B(g) --> C(g)

A(s) + B(g) -->2C(g)

Calculate the ∆Hº (on a per mole basis) for the HCl/NaOH neutralization. You may assume that the specific heat and density of the resulting solution to be the same as water. Be sure to use the combined total volumes of HCl and NAOH when calculating the total mass for this reaction. Remember to take into account the moles of limiting reagent when calculating the ∆Hº on a per mole basis.

Exact Concentrations: HCl = .9637 NaOH = 1.016

Trial 1 : temp of HCl = 19 degrees C Temp of NaOH = 19 degrees C constant temp of HCl & NaOH = 24.5 degrees C

Trial 2 : temp of HCl = 20 degrees C Temp of NaOH = 20 degrees C constant temp of HCl & NaOH = 24 degrees C

synthesis of Ethanol by fermentation

(a) Calculate the atom economy and reaction efficiency of your ethanol synthesis. (b) Describe some green features of your synthesis, and any that aren't so green.

In addition to mass balance, oxidation-reduction reactions must be balanced such that the number of electrons lost in the oxidation equals the number of electrons gained in the reduction. This balancing can be done by two methods: the half-reaction method or the oxidation number method. The half-reaction method balances the electrons lost in the oxidation half-reaction with the electrons gained in the reduction half-reaction. In either method H2O(l), OH?(aq), and H+(aq) may be added to complete the mass balance. Which substances are used depends on the reaction conditions.

Acidic solution

In acidic solution, the nitrate ion can be used to react with a number of metal ions. One such reaction is

NO3?(aq)+Sn2+(aq)?NO2(aq)+Sn4+(aq)

Since this reaction takes place in acidic solution, H2O(l) and H+(aq) will be involved in the reaction. Places for these species are indicated by the blanks in the following restatement of the equation:

NO3?(aq)+Sn2+(aq)+     ????NO2(aq)+Sn4+(aq)+     ???

Part A

What are the coefficients of the reactants and products in the balanced equation above? Remember to include H2O(l) and H+(aq) in the appropriate blanks. Your answer should have six terms.

Enter the equation coefficients in order separated by commas (e.g., 2,2,1,4,4,3). Include coefficients of 1, as required, for grading purposes.

Basic solution

Potassium permanganate, KMnO4, is a powerful oxidizing agent. The products of a given redox reaction with the permanganate ion depend on the reaction conditions used. In basic solution, the following equation represents the reaction of this ion with a solution containing sodium iodide:

MnO4?(aq)+I?(aq)?MnO2(s)+I2(aq)

Since this reaction takes place in basic solution, H2O(l) and OH?(aq) will be shown in the reaction. Places for these species are indicated by the blanks in the following restatement of the equation: MnO4?(aq)+I?(aq)+     ????MnO2(s)+I2(aq)+     ???

Part B

What are the coefficients of the reactants and products in the balanced equation above? Remember to include H2O(l) and OH?(aq) in the blanks where appropriate. Your answer should have six terms.

Enter the equation coefficients in order separated by commas (e.g., 2,2,1,4,4,3). Include coefficients of 1, as required, for grading purposes.

What is the pH of a solution containing 10 g of HCOOH, formic acid dissolved in enough water to make 250 mL of solution?

The answer is B, but I really need a detailed explanation for this.

Equal volumes of the following pairs of solutions are mixed. Which pair will produce a buffer solution?

A. 0.10 mol L-1 HCl and 0.05 mol L-1 NaOH

B. 0.10 mol L-1 HCl and 0.15 mol L-1 NH3

C. 0.10 mol L-1 HCl and 0.05 mol L-1 NH3

D. 0.10 mol L-1 HCl and 0.20 mol L-1 CH3COOH

E. 0.10 mol L-1 HCl and 0.20 mol L-1 NaCl

Hi, I need the Lewis Structure, the Molecular Geometry, and polarity of these compounds:

CH2Cl2

BH3

PH3

SF4

PCl5

Thank you very much

How do you make a 10, 20, and 30% solution of sucrose?

   b. A student measured out 0.509g of galactose and dissolved it in 25.0mL of water. 10.0 cm of sample was added to the cell, producing an angle of 204.4. If the blank's angle was 202.7, what is the observed angle of rotation for the sugar solution, the specific rotation of the sugar, and the percent difference.

c. Calculate the concentration of sucrose using the following information:  blank's angle = 180.0, sample height = 9.7cm, and sample's angle = 186.3.

True or False

a. a buffer consists of any acid and any base mixed together

b. proteins tend to precipitate at high salt concentration

c. Coulomb's law measures the standard reduction potential between charged molecules

d. A compound with a large dipole moment will be non polar

e. beta mercaptoethanol and performic acid are used to reduce disulfide bonds

f. water has a high heat capacity and a high dialectric constant

g. biomolecules with a chiral center will exist in the body as a racemic mixture

h. alanine is a zwitterion at pH 7.0

i . free protons are never observed in aqueous systems

j. electrophoresis seperates molecules based upon partitioning between a mobile and stationary phase

A sample of propane gas (C3H8) having volume of 1.80L at 25oC and 1.65atm was mixed with a sample of oxygen gas having a volume of 35.0L at 31oC and 1.25atm. The mixture was ignited to form carbon dioxide and water. Write the balanced reaction. What is the limiting reagent? What is the maximum number of grams of water which can form from this reaction? Find the number of moles of excess reactant at STP.

Consider each of the following systems for long times, at which their behacioor is time invariant. Identify each system as equilibrium or steady state.

1) A hose supplies water at a constant rate to a bucket with a hole in it. A constant water level is maintained

2)A mixture of reacting gas molecules is constrained to a fixed temperature, e.g., H2, O2 and H2O at 600 K.

3) Ice floats in water, thermally insulated from its surroundings.

4) Molten steel is poured into a continuous casting mill while withdrawing solid steel from the bottom.

(5) A foil birthday balloon is brought into a hot room.

Assuming you have 0.075 grams of benzoic acid in 1 mL of water

A) Calculate the moles of benzoic acid.

B) Assuming you used 1 mL of 2 M NaOH calculate the moles of NaOH present in solution.

C) Is the amount of NaOH sufficient to react with all of the benzoic acid?

Complete and balance each of the following equations for combustion reactions.

Express your answer as a chemical equation. Identify all of the phases in your answer.

A. C4H6(g)+O2(g)?

B.   C(s)+O2(g)?

C. CS2(s)+O2(g)?

D.   CH4O(l)+O2(g)?