Physical Chemistry Answers

Suppose we have 8 distinguishable particles that have a total energy equal to 6 units. The distribution for this system are labelled (no, n1, n2 , n3 ). Calculate the number of microstates (W) for each of the following distributions; (a) ( 6, 0, 0, 2), (b) ( 5, 1, 1, 1), (c) (4, 2, 2, 0), (d) (2, 6, 0, 0)

What will be the number of microstates (W) when 10 molecules are equally distributed among five energy levels.What is the value of W if one molecule is removed from one state and added to another?

An aliphatic carboxylic acid reacts with an alcohol and the following equilibrium is established RCOOH+R'CH^2OH=RCOOCH^2R'+H^2O what is the number of constituents and the number of components in the system

If 17.3g of powdered aluminium are allowed to react with excess Fe2O3, how much heat is produced?

1. In acidic solution, dichromate ion oxidizes 0xalic acid, H2C2O4 (aq), to CO2 (g) in a reaction with Eocell =1.81V.

Cr2O72-(aq) +  3 H2C2O4(aq)  +  8H+(aq) →  2Cr3+(aq)  + 7H2O +  6CO2(g) ,

) Calculate the entropy change at a constant pressure of 1 atm when one mole of liquid 

NH3 at -40 is transformed to the gaseous state at 200 using the following data: ℃ ℃

Cp for NH3 (l) = 17.9 Cal K-1 mol-1 ; Cp for NH3(g) = (8.04 + 7.0 x 10-4 T + 5.1 x 10-6

T 2

 )Cal K-1 mol-1 ; Boiling Point of NH3 (g) = 239.7 K; ΔvapH239.7 = 5560 Cal mol-1

) In the solid state at 0 K, nitric oxide is capable of existing in two orientations such as 

NONO and NOON, which have equal probabilities. Calculate the molar entropy of 

NO at 0 K?

How many moles of NO(g) can be produced in the reaction of 3.00 mol NH3(g) and 4.00 mol O2(g) ? 

4 NH3(g) + 5 O2(g) = 4 NO(g) + 6 H2O(l)

A solution contains 20g of solute in 180g of solvent. If the solvent is water, what is the concentration of the solution in terms of mass by mass percentage

A. 11.%

B. 22.2%

C. 10%

D. 20%

Please show working

At 2.00K the vapour pressure of liquid helium is 3173 PA and the heat of vaporisation is 92.048J/mol. Calculate the Lowest temperature which can be obtained by pumping on a a Dewar flask of liquid helium with a pumping system which will achieve an ultimate steady-state pressure of 133.32 PA. You may assume that the molar volume of the liquid is negligible and the vapour behaves like an ideal gas.

b) If the heat into the Dewar is 4.184J per minute, estimate the pumping speed in m^3 per minute at 133.32 PA and 309K ( temperature of gas at the pump).