Question

The distance between the carbon atom and the oxygen atom in a carbon monoxide molecule is 1.1 Å. Given, mass of carbon atom is 12 a.m.u. and mass of oxygen atom is 16a.m.u., calculate the position of the center of mass of the carbon monoxide molecule

• A. 6.3 Å from the carbon atom
• B. 1 Å from the oxygen atom
• C. 0.63 Å from the carbon atom
• D. 0.12 Å from the oxygen atom

Answer 1

Answer: (C)

0.63 Å from the carbon atom

Answer 2

Let carbon atom is at the origin and the oxygen atom is placed at x-axis

$m_{1} = 12$, $m_{2} = 16$, ${\overset{\rightarrow}{r}}_{1} = 0\widehat{i} + 0\widehat{j}\text{and}{\overset{\rightarrow}{r}}_{2} = 1.1\widehat{i} + 0\widehat{j}$

$\overset{\rightarrow}{r} = \frac{m_{1}\overset{\rightarrow}{r_{1}} + m_{2}\overset{\rightarrow}{r_{2}}}{m_{1} + m_{2}}$ $= \frac{16 \times 1.1}{28}\widehat{i}$

$\overset{\rightarrow}{r} = 0.63\widehat{i}$ i.e. 0.63 Å from carbon atom.