Question

The following data were obtained in an experiment on inversion of cane sugar in the presence of 0.1N HCl.
Time(min) 0 60 120 180 360 infinity
Angle of
Rotation 13.1 11.6 10.2 9.0 5.87 -3.8
After what time would you expect a zero reading in Polarimeter........its urgent can someone help me fast!

Answer 1

WOW Very interesting question i Love it :)

Answer 2

@chmvijay will u plz solve it.....

Answer 3

yup it is theorotical just use chemical kinetics and answer this @nincompoop

Answer 4

hope @nincompoop answers this :)

Answer 5

me too hopind the same......lets see...its not supposed to be very difficult .... it is class 12 question....ISC board @chmvijay

Answer 6

*hoping

Answer 7

ok here's the only hint
formula\[k =\frac{ 2.303 }{ t }\log_{10}\frac{ r_{0}-r _{\infty} }{ r_{t}-r _{\infty} } \]

Answer 8

@nincompoop @chmvijay @Frostbite i got to go back to work.......if you guys get the answer plz do reply here........thanks! Bye will be back soon

Answer 9

ok fine me to leaving to BED will see it hope @nincompoop solves this :)

Answer 10

I can't… LOL

Answer 11

@electrokid

Answer 12

I guess i will have to ask this to my instructor...!

Answer 13

in the formula
\[k={2.303\over t}\log_{10}\frac{r_0-r_\infty}{r_t-r_\infty}\]
k = rate of reaction (interms of change in optical activity)
t = time
r = angles of rotation
from this, we calculate the rate of reaction
\[
k={2.303\over120}\log_{10}\frac{13.1-(-3.8)}{10.2-(-3.8)}\\
k=1.57\times10^{-3}
\]
use the equation again, to find "t" when r_t=0
rearranging, the terms,
\[
t={2.303\over 0.00157}\log_{10}\frac{13.1-(-3.8)}{0-(-3.8)}\\
\Large\boxed{t=950\,{\rm min}\\
t=15\,{\rm hr}\;50\,{\rm min}}
\]

Answer 14

@electrokid Thanks a lot!!! It was great help....

Answer 15

@electrokid nice :)