LM 53 - Group Practice Questions

To make a 4 cup pot of green tea, one must heat the water to the boiling point (100°C) at standard pressure. If the pot contains 680 grams of water, and the temperature at the tap is 20.0°C, how much heat must be absorbed by the water? (Use 4.18 J/g °C for the specific heat of water.)

• 28400 J

• 56800 J

• 227000 J

• 280000 J

A student wants to identify a 4.78 g unknown metal sample. She applies 3.00 joules of heat to the sample and measures a temperature change from 24.94°C to 28.86°C. Based on the information and the table above, what is the most likely identity of the metal?

• Gold

• Lead

• Copper

• Aluminum

Refer to the table above. A student wants to fry an egg in a 1.77 kg iron skillet. An egg will become firm at 70°C.

If the skillet begins at room temperature of 25°C, what is the minimum amount of energy that must be transferred to the skillet in order to fry the egg?

• 12.7 joules

• 12,700 joules

• 35.4 joules

• 35,400 joules

A cast iron skillet is used to fry bacon. For optimal frying, the pan must be heated to about 178°C from a room temperature of 22.0°C. It is known that 1.58 x 10 Joules of heat energy are absorbed by the pan to reach the desired temperature and the specific heat of iron is 0.450 J/g°C.

What must the mass of the skillet be?

• 12700 g

• 2250 g

• 110000 g

• 1970 g

Carbon tetrachloride was commonly used as an organic solvent until it was found to be carcinogenic. How much heat is required to raise the temperature of 10.35 g of CCl₄ from

32.1°C to 56.4°C?

The specific heat of CCl₄ is 0.85651 J/g °C.

• 206 J

• 218 J

• 193 J

• 215 J

50.0 grams of an unknown metal is heated to 100.0°C and then placed in a calorimeter with

250.0 mL of water. If the final temperature of the metal is 29.1°C and the calorimeter absorbed 824 Joules of energy, what is the specific heat of the unknown metal?

• 0.165 J/g °C

• 0.232 J/g °C

• 0.566 J/g °C

• 2.32 J/g °C