Describe the process of electrospray ionisation of a sample in a time-of-flight (TOF) mass spectrometer.

Give an equation to represent the ionisation of a general molecule, symbolised as $R$, in this process.

A molecule $R$ is ionised by electrospray ionisation in a TOF mass spectrometer.

• The $R{H}^{+}$ ion has a kinetic energy of $2.16\times 10^{-15}J$.
• This ion takes $1.50\times 10^{-5}s$ to reach the detector.
• The length of the flight tube is $1.80m$.

Calculate the relative molecular mass of $R$.

Use the equations: $KE=\frac{1}{2}m{v}^2$ where $m=mass\; (kg)$ and $v={speed\; (m\; s}^{-1})$.

The Avogadro constant, $L=6.022\times 10^{23}{mol}^{-1}$.