A plant virus is found to consist of uniform cylindrical particle of `150 Å` in diameter 5000 Å long. The specific volume of the virus is 0.75 `mLg^(-1)`. If the virus is considered to be a single particle, find its molar mass.

Explanation

`"Radius of virus (r )"=(150)/(2)=75Å`
`=75xx10^(-8)cm`
`h=5000Å=5000xx10^(-8)cm`
`"Volume of one virus particle "=pir^(2)h`
`=(22)/(7)xx(75xx10^(-8))^(2)xx(5000xx10^(-8))`
`=8.84xx10^(-17)cm^(3)`
`"Mass of one virus particle"=("Volume")/("Specific volume")`
`=(8.84xx10^(-7))/(0.75)`
`=1.179xx10^(-16)g`
`"Molecular mass"="Mass of a virus particle"xx"Avogadro number"`
`=1.179xx10^(-16)xx6.023xx10^(23)=7.10xx10^(7)" g mol"^(-1)`