What are the mole fraction (X) and molality (m) of ethanol (C₂H₅OH) in an aqueous solution that is 45.0% ethanol by volume? The density of water is 1.00 g/mL and that of ethanol is 0.789 g/mL.

mole fraction = ?????;

molality =

??? m

1. A galvanic cell is based on the following half-reactions at 285 K:

Ag⁺ + e^- → Ag     E^o = 0.803 V  
H₂O₂ (aq) + 2 H⁺ + 2 e^- → 2 H₂O     E^o = 1.78 V

What will the potential of this cell be when [Ag⁺] = 0.571 M, [H⁺] = 0.00341 M, and [H₂O₂] = 0.895 M?

Please show full work .

How much heat (in kJkJ) is required to warm 13.0 gg of ice, initially at -14.0 ∘C∘C, to steam at 108.0 ∘C∘C? The heat capacity of ice is 2.09 J/g⋅∘CJ/g⋅∘C and that of steam is 2.01 J/g⋅∘CJ/g⋅∘C.

74) Epoxy is a(n) ?

a) elastomer

b) thermoset

c) thermoplastic

d) composite

.

75) In tempering of steel, temperature treatments around 400 °C are used to?

a) reduce brittleness and increase ductility (toughen) by transforming martensite morphology

b) increase strength and hardness by locking in martensite structure

c) increase strength and hardness by causing lower density glass layer to form on surface

d) reduce brittleness and increase ductility (toughen) by causing martensite morphology to form

.

76) Surface carburizing of steel involves

a) burning excess carbon out of the iron carbon alloy to form steel.

b) introducing extra carbon into surface of austenite to harden and toughen surface with quenching and formation of martensite.

c) forming martensite on the surface through rapid cooling to harden and toughen surface with quenching.

d) introducing extra carbon into surface of cementite to harden and toughen surface with quenching.

Please answer all of them without guessing!!! Thanks

Use data from Appendix IIB in the textbook to calculate the equilibrium constants at 25?C for each of the following reactions.

2NO(g)+O2(g)?2NO2(g) .

Express your answer using two significant figures.

With the aid of a clearly labelled schematic diagram, illustrate the main layout of a flame atomic absorption spectrometer with continuum source background correction. Describe briefly the purpose of each component.

Your diagram should include reference to the following components:

The hollow cathode lamp                           The flame and burner

The deuterium lamp                                   The monochromator

The modulator or chopper                          The detector

What is the effect of the following on the volume of 1 mol of an ideal gas?

(a) The pressure from 760 torr to 202 kPa, and the temperature changes from 37C to 155k.

(b) The temperature changes from 305K to 32C, and the pressure changes from 2 atm to 101k Pa.

(c) The pressure is reduced by a factor of 4 ( at constant T).

Which metal can react with an acid? Cu, Ag, Al, Au (Answer is Al) Can someone explain why?

1) A 0.23 g sample of an unknown monoprotic acid is titrated with 0.11 N NaOH. 23.89 mL of NaOH is required to reach the equivalence point. What is the molar mass of this acid?

2) You perform a phenolphthalein titration on a 0.26 g sample of an unknown organic acid, which requires 33.78 mL of 0.1008 N NaOH to reach the endpoint.

a) What is the equivalent weight (estimate) for this acid?

b) Assume the acid is monoprotic and calculate its molar mass. Assume the acid is diprotic and calculate its molar mass. Now that you have two potential molar mass values, using the list of acids in the lab, do you think this acid is monoprotic or diprotic? Explain your rationale.

Insulin sequence As reported in 1945, Sanger reacted insulin with FDNB and hydrolyzed the resulting protein. He found many free amino acids, but only three DNB-aa

why is proline isomerization often a rate limit step in protein folding? Explain

Write the half reaction for the anode and cathode for the following electrochemical cells. which metal acts as the anode and which acts as the cathode. For each cell, combine the half reactions and write the overall cell reaction.

a. Zn/Cu

b. Fe/Cu

c. Mg/Cu

d. Pb/Cu

e. Sn/Cu