### Sample Question: Electron Spin and Orbital Angular Momentum

From atomic structure we know an electron can only have has an intrinsic spin vector of s = 1/2. From quantum mechanics the magnitude of......

### Magnetic Sector Mass Spectrometer

A cation of charge q travelling with a velocity v enters a magnetic field B at right angles (θ = 90°) to the field and......

### Sample Question: Methane Structure

Methane is tetrahedral, that is it fits inside a cube with the carbon atom at the intersection of any two diagonals, which is at the......

### HMO Theory for Cyclobutadiene

(a) Write down the Hiickel secular determinant for the four C-atoms of cyclobutadiene in terms of x, where x = (α – E)/ β.......

### Calculate Vector Addition Dipole Moments of Molecules?

As vectors have magnitude and direction, the first thing to decide is the direction of the dipole. The electric dipole moment (or just dipole moment)......

### Calculate the Absorption of Light by Polar Molecules?

It is possible to arrange molecules so that the bond dipoles all point in a particular direction. Below Figure shows the alignment of carbonyl bonds......

### Time of Flight Mass Spectrometer

A time-of-flight (TOF) mass spectrometer is sketched below. The TOF MS is all under a vacuum. A pulsed laser fires a pulse of light......

### Sample Question: Hydrogen Halide Dipole Moments

The magnitudes of the four hydrogen halide dipoles are given below. Firstly, using vector notation, express the magnitudes of the HF, HBr and the HI......

### Sample Question: HMO Theory for Cyclopropenyl Cation, Radical and Anion

(a) Write down the Hiickel secular determinant for the cyclic three C-atoms in terms of x, where x = (α – E)/β. (b) Solve the......

### Sample Question: HMO Theory for 1,3-Butadiene

(a) Write down the Hiickel secular determinant for the four C-atoms of butadiene in terms of x, where x = (α – E)/β. (b) Solve......

### Sample Question: HMO Theory for the Allyl Cation, Radical and Anion

=> Write down the Hiickel secular determinant for the acyclic three C-atoms in terms of x, where x = (α – E)/ β. => Solve......

### Chemical Analysis of the Spectra of Three or More Components

A student in their lab dass measured the following spectroscopic data for some pure samples of three indicators thymol blue (TB), semithymol blue (STB) and......

### Chemical Analysis of Well Separated Spectral Regions

For a single absorbing molecular species in solution, the Beer-Lambert Law states that A = Ɛ l c where A is the absorbance, e is......

### What is the Speed of Chemical Reactions?

The Arrhenius equation is an important equation in chemical reactions kinetics where k is the rate constant, A is the pre-exponential factor, Ea the activation......

### Sample Question: Chemistry and Simultaneous Equations

There is a linear relationship between the Celsius and Fahrenheit temperature scales such that TF = mTc + C Given that the freezing point of......