Part 1 Suppose you are given 14.4g of an unknown material and you have to determ

Question

Part 1

Suppose you are given 14.4g of an unknown material and you have to determine what it is. Using the equipment, you determine that the initial temperature of the material is 20°C and when you put it in the Dewar flask 7.0g of nitrogen evaporate by absorbing heat from the material. What is the specific heat of the material? Assume you have already accounted for the nitrogen that evaporates due to contact with the air in the room.

Question 1 options:

450 J/(kg °C), therefore the material could be iron.

230 J/(kg °C), therefore the material could be silver.

390 J/(kg °C), therefore the material could be copper.

130 J/(kg °C), therefore the material could be gold.

Part 2

You finally decide to take some liquid nitrogen from the physics lab and freeze the 1/2 pound of beans which were sitting in your vegetable basket at 20 C, rather than cook and eat them as your mother would have you do. Beans are mostly water, like all living things. If the specific heat of water is approximately 1 cal/g/C and latent heat of fusion of water is approximately 80 cal/g, and the latent heat of vaporization of liquid nitrogen is 45 cal/g as measured by you, how much liquid nitrogen should you take from the lab (approximately)?You don't want to take a whole lot more than you really need.

Question 2 options:

50 g

250 g

1.5 kg

3 kg

6 kg

500 g

450 J/(kg °C), therefore the material could be iron.

230 J/(kg °C), therefore the material could be silver.

390 J/(kg °C), therefore the material could be copper.

130 J/(kg °C), therefore the material could be gold.

Explanation / Answer

a)option c

b)option b

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