Answer:
1.29649
488.08706 nm

231715700.28346 m/s
Step-by-step explanation:
n denotes refractive index
1 denotes air
2 denotes solution
= 632.8 nm
From Snell's law we have the relation

Refractive index of the solution is 1.29649
Wavelength is given by

The wavelength of the solution is 488.08706 nm
Frequency is given by

The frequency is


The speed in the solution is 231715700.28346 m/s