Question

1Would a liquid’s refractive index measured at a high altitude be different from that measured at sea level? Explain IK the answear is yes i just do not know why?

2. A student obtains a refractive index reading of 1.4684 at 200C. Calculate the refractive index at 25oC and18oC. Show all your work to get a full credit. RI(25)=1.4684-(0.0004*5)=1.4664 RI(18)=1.4684+(0.0004*2)=1.4692 This is what i got i just dont know if its right or not.

Answer 1

1)

Yes.

This is because with altitude, temperature decreases and this decrease in temperature alters the liquid’s refractive index.

The speed of light in a substance is slower than in a vacuum since the light is being absorbed and reemitted by the atoms in the sample. Since the density of a liquid usually decreases with temperature, it is not surprising that the speed of light in a liquid will normally increase as the temperature increases. Thus, the index of refraction normally decreases as the temperature increases for a liquid. For many organic liquids the index of refraction decreases by approximately 0.0005 for every 1 °C increase in temperature. However for water the variation is only about -0.0001/°C.

2)

For your liquid, I assume your factor of change is +- 0.004.

All you have done is correct, decrease in refraction index with temperature increase (25oC) and increase in refraction index with temperature decrease (18oC).