In order to calculate the angle of refraction, we can use the law of refraction below:
Where n1 and n2 are the index of refraction and theta1 and theta2 are the incident angle and the refraction angle.
So, using n1 = 1.0003, n2 = 2.42 and theta1 = 40.5°, we have:
Therefore the angle of refraction is 15.6°.