Answer
$\Delta \theta_{refraction} = 0.23^{\circ}$
Work Step by Step
Find the angles of refraction using Snell’s law. Here “1” designates air, and “2” designates the glass.
First piece of glass:
$$n_1sin\theta_1= n_2sin\theta_2$$
$$\theta_2=sin^{-1}(\frac{n_1}{n_2}sin\theta_1) $$
$$=sin^{-1}(\frac{1.00}{1.4831}sin65.00^{\circ}) =37.67^{\circ}$$
Second piece of glass:
$$\theta_2=sin^{-1}(\frac{1.00}{1.4754}sin65.00^{\circ}) =37.90^{\circ}$$
The difference in refraction angles is $\Delta \theta_2 = 0.23^{\circ}$.