The moment of inertia of `HCl` molecule about an axis passing through its centre of mass and perpendicular to the line joining the `H^+` and `Cl^-` ions will be (if the inter atomic distance is `1A^@`)

Explanation

`r=1Å=10^(-10)m , m_(1)=1 am u, m_(2)=35.5 am u`
Reduced mass `mu=(m_(1)m_(2))/(m_(1)+m_(2))=0.976 am u`
`~= 1.624xx10^(-27)kg [ :. 1 am u=1.67xx10^(-27) kg]`
Moment of inertia about an axis passing through centre of mass of two particle system and perpendicular to the line joining them is
`I=mur^(2)=1.624xx10^(-47) kg m^(2)`