Calculate the diffusion coefficient of N₂ at 100 Pa, 100 kPa an 20 MPa (temperature T = 20 degrees celsius).

1.What will happen when you add ammonium hydroxide to sodium hydroxide?

2.Explain why acetic acid and sodium acetate can exist in an equilibrium but hydrochloric acid and sodium hydroxide cannot.

3.How will cobalts equilibrium with 1M HCL differ from its equilibrium with concentrated H2SO4?

Suppose two blocks of iron, each having 1 mol of iron atoms, are at differing temperatures and are then brought together in an otherwise isolated system. One of the blocks is at 273.15 K and the other is at 373.15 K and the process is carried out at 1 bar pressure.

a.) Would you expect ∆Ssys < 0, ∆Ssys = 0, ∆Ssys > 0 ?

b.) Using common sense and high school physics (and perhaps the First Law), what is the common final temperature of the two blocks?

c.) Calculate ∆Ssys for the process (use Table 4.1 for any needed molar heat capacities needed, and assume that the molar heat capacities are independent of T).

d.) What is q for the isolated system? How does this value of q and the result of part C relate to the Clausius inequality: final initial d q S T − ∆ ≥ ∫ ?

e.) Interpret this change in entropy in terms of the ordering-disordering effects involved in the transfer of given amount of heat from a block at higher temperature to one at a lower temperature (i.e. the disordering effect of adding a given q to the cooler block vs the ordering effect of removing the same q from the hotter block).

Molar heat capacity of Fe(s) ==> Cp,m (J / mol*K) = 25.1

The reaction 2H2S(g)⇌2H2(g)+S2(g) Kc=1.67×10−7 at 800∘C is carried out with the following initial concentrations: [H2S] = 0.325 M , [H2] =0.125 M , and [S2] = 0.00 M. Find the equilibrium concentration of [S2].

how does hot water separate silver (1) chloride from lead (2) chloride?

Copper reacts with dilute nitric acid according to:
3 Cu(s) + 8 HNO3(aq) ? 3 Cu(NO3)2(aq) + 2 NO(g) + 4 H2O(l)

If a copper penny weighing 3.045-g is dissolved in 37.23 mL of 3.750 M nitric acid and the resultant solution is diluted to 50.00 mL in a volumetric flask, what is the final concentration of NO3- in the solution?

A. An unknown radioactive substance has a half-life of 3.20hours . If 10.6g of the substance is currently present, what mass A0 was present 8.00 hours ago?

B. Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 45.0{\rm \\%} of an Am-241 sample to decay?

C. A fossil was analyzed and determined to have a carbon-14 level that is 20{\rm \\%} that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?

Consider the cadmium electrode, whose half-reaction is shown below. Calculate the potential of the electrode at 25 °C under the given conditions. A) Immersed in a 0.0120 M solution of CdBr2. B) Immersed in a 0.0490 M NaOH solution that is saturated with Cd(OH)2. Ksp for Cd(OH)2 is 7.2 × 10–15. C) Immersed in a 0.0140 M Cd(NH3)42 and 0.375 M NH3 solution. β4 for Cd(NH3)42 is 3.63 × 106.

Using the following portion of the activity series for oxidation half reactions

K(s) → K+ (aq) + e-

Al(s) → Al3+ (aq) + 3e-

Fe(s) → Fe2+ (aq) + 2e-

Sn(s) → Sn2+ (aq) + 2e-

Determine which reaction will occur.

A) Al3+(aq) with Fe(s)

B) Al(s) with Sn(s)

C) K+(aq) with Fe2+(aq)

D) K(s) with Sn2+(aq)

Complete each of the following nuclear reactions and calculate the energy change (in units J/mol of reactant) associated with each one. (Al-27 = 26.981538 amu, He-4=4.002603 amu, P-30=29.981801, W-179=178.94707, Ta- 179=178.94593)

(for below x / y , x = mass number while y = atomic number)

a. 27 / 13 Al + 4 / 2 He → 30 / 15 P + ______

b. 179 / 74 W + ______ →179 / 73 Ta

What type(s) of intermolecular forces exist between PH3 and CO32-?

A sample containing 2.00 x 10-2 mmol of Cu(NO3)2 and 3.00 x 10-2 mmol of K2SO4 is passed through an anion-exchange column. Calculate the volume of 0.0100 M HCl needed to titrate the eluate.

What is the change of pH upon addition of 10.0 ml of HCl 3.0 M to 750. ml of the following:

- pure water

- 0.1 M formic acid

- 0.1M acetate of sodium

- a buffer made of 0.1M potassium nitrite and 0.08 M nitrous acid.

Do you expect the ionization energies of anions of group 17 element to be lower than, higher than, or about the same for neutral atoms of the same group?

use the method of half reactions to balance the following equations: a) CrI3 (s) + Cl2 (g) ----> CrO 2-4 (aq) + IO-4 (aq) (basic) b) C2H5OH (aq) + I-3 (aq) ----> CO2 (g) + CHO-2 (aq) + CHI3 (aq) + I- (aq) (acidic)