Answer
See explanation.
Work Step by Step
The speed and the wavelength of the light will be affected by the fluid, but not the frequency.
a. For violet, $\lambda_v=\frac{380nm}{1.34}=284nm$, and for red, $\lambda_r=\frac{750nm}{1.34}=560nm$.
The wavelength range is 284 nm to 560 nm.
b. Calculate the frequency in air. The low frequency: $$f_r=\frac{c}{\lambda_r}=\frac{3.00\times10^8m/s}{750\times10^{-9}m}=4.00\times10^{14}Hz$$
The high frequency: $$f_v=\frac{c}{\lambda_v}=\frac{3.00\times10^8m/s}{380\times10^{-9}m}=7.89\times10^{14}Hz$$
c. $v=\frac{3.00\times10^8m/s }{1.34}=2.24\times10^8m/s $.
