Question

A plant virus is found to consist of uniform cylindrical particles of 150A° in diameter and 5000°A long . The specific volume of the virus is 0.75cm^3/g . If the virus is considered to be a single particle , find its molecular weights.[v=πR^2.L]

Answer 1

i) Volume of virus = πr² L(Volume of cylinder)
(ii) Mass of single virus = Volume/Sp. Volume
(iii) Molecular mass of virus
= Mass of single virus × 6.02×10²³
Volume of virus = π r²1
= 22/7 ×150/2 ×150/2 ×10^-16 ×500 ×10^-8
= 0.884 × 10^-16 cm³
Weight of one virus = 0.884 ×10^-16/0.75 g
= 1.178 ×10^-19 g
∴ Mol. wt. of virus = 1.178 ×10^-19 × 6.02 × 10²³
= 7.09 ×10⁷