Correct Answer - 630
Mass = 20 gm
Volume = 200 ml
`C=(mass)/(volume)=20/200=0.1gm//ml`
Length of tube (l) = 10 dm
Optical rotation `theta=30^(@)`
`" "alpha=(theta)/(Cxxl)`
`" "alpha=30/(0.1xx10)=30`
(a) If solution is dilute to one litre then volume
V= 1000 ml
`theta`=?
`alpha=(theta)/(Cxxl),30=(theta)/(20/1000),theta=6^(@)`
(b) Specific rotation does not change with change in conc. or volume of length etc. therefore it is `30^(@)`