posted 10 months ago

O What is the mathematical operator in this equation?

(10%) Under what conditions is the function z(t) = B sin (wt) a solution of Eq. 6.2? Justify your answer by showing a detailed proof.

posted 10 months ago

1. (10%) What is the minimum possible value of the partition function for this system? Justify

O What is the value of BAɛ for this system?

3. (10%) Estimate the number of quantum states which are populated.thermally

4. (10%) If the temperature is doubled, estimate the number of thermally populated states.

posted 10 months ago

1. (10%) Calculate the contribution from translation and rotation to the molar heat capacity of the Cl2 gas at 400 K.

2. (10 %) Calculate the contribution from vibration to the molar heat capacity of the Cl2 gas at 400 K, given that diatomic molecule Cl, has a vibrational wavenumber of 565 cm¬1.

3. (10%) Predict the molar heat capacity of Cl2 gas at 400 K and compare your result with the experimental molar heat capacity of Cl2 , Cy × 29 J/(K mol) at400 K.

6) Calculate the average internal energy <U> for the Cl2 gas at 400 K.

posted 11 months ago

E_{A}=-\frac{1.436}{r} \quad \text { and } \quad E_{R}=\frac{7.32 \times 10^{-6}}{r^{8}}

For these expressions, energies are expressed in electron volts (eV) per Na*–Cl¯ pair, and r is-the distance in nanometers (nm). The net energy En is just the sum of the preceding two expressions.

(a) Superimpose on a single plot EN, ER, and EA versus r up to 1.0 nm.

(b) On the basis of this plot, determine (i) the equilibrium spacing ro between the Na* and Cl-ions, and (ii) the magnitude of the bonding energy Eo between the two ions.

posted 11 months ago

posted 11 months ago

posted 11 months ago

posted 11 months ago

(b) Schematically plot the curve of net force (FN) vs. interatomic separation (r) for two isolated atoms. Indicate on the plot the equilibrium separation ro.

(c) Briefly describe the behaviors of the net potential energy and the net force at the vicinity of equilibrium separation ro, i.e. how the energy and force change with the change of interatomic separation around ro.

posted 11 months ago

posted 1 years ago

(b) Which ionisable groups are likely to contribute to the buffering capacity of the intracellular medium at normal intracellular pH values? What other mechanisms are available for maintaining intracellular pH values at appropriate values?

(c) The pKa of methanoic acid is 3.8. What ratio of methanoic acid to sodium methanoate would be necessary to give a solution of pH 4.5?

(d) Methanoic acid/methanoate is going to be used as a buffer for a reaction. The unbuffered reaction at pH 4.5 results in a decrease in the pH of 2.5 units. What is the minimum concentration of the buffer needed to prevent the pH falling below 4.25?