Q: How much heat is required to raise the temperature of 2 kg of water by 5 K? (Specific heat of water $$c = 4190\ \text{J kg}^{-1}\ \text{K}^{-1})$$

$$Q = 4190 \times 2 \times 5 = 41,900\ \text{J}$$

Q: Which unit is used for specific heat capacity in the SI system?

$$\text{J kg}^{-1}\ \text{K}^{-1}$$

Q: If you have 0.5 moles of water and want to raise its temperature by 10 K, how much heat is required? (Molar heat capacity of water $$C = 75.4\ \text{J mol}^{-1}\ \text{K}^{-1})$$

$$Q = 75.4 \times 0.5 \times 10 = 377\ \text{J}$$

Q: Convert 100 calories to Joules. (1 cal = 4.184 J)

$$100 \times 4.184 = 418.4\ \text{J}$$

Q: A 0.1 kg sample of copper is heated from 20°C to 50°C. How much heat is required? (Specific heat of copper $$c = 390\ \text{J kg}^{-1}\ \text{K}^{-1})$$

$$Q = 390 \times 0.1 \times 30 = 1,170\ \text{J}$$

Q: A 0.2 kg sample of aluminum is heated by 15 K. How much heat is required? (Specific heat of aluminum $$c = 910\ \text{J kg}^{-1}\ \text{K}^{-1})$$

$$Q = 910 \times 0.2 \times 15 = 2,730\ \text{J}$$

Q: A 0.05 kg sample of ethylene glycol is heated by 10 K. How much heat is required? (Specific heat of ethylene glycol $$c = 2386\ \text{J kg}^{-1}\ \text{K}^{-1})$$

$$Q = 2386 \times 0.05 \times 10 = 1,193\ \text{J}$$

Question 1

Which of the following statements best describes the concept of heat as discussed in the study materials?

Accepted Answer

Heat is the non-mechanical exchange of energy between two systems due to their temperature difference.

Question 2

A paddle wheel is used to stir water, raising its temperature. According to Joule's experiments, which equation relates the work done ($$W) to $$the heat ($$Q) $$transferred?

Accepted Answer

$$Q = W$$

Question 3

How much heat is required to raise the temperature of 2 kg of water by 5 K? (Specific heat of water $$c = 4190\ 	ext{J kg}^{-1}\ 	ext{K}^{-1})$$

Accepted Answer

$$Q = 4190 	imes 2 	imes 5 = 41,900\ 	ext{J}$$

Question 4

Which unit is used for specific heat capacity in the SI system?

Accepted Answer

$$	ext{J kg}^{-1}\ 	ext{K}^{-1}$$

Question 5

If you have 0.5 moles of water and want to raise its temperature by 10 K, how much heat is required? (Molar heat capacity of water $$C = 75.4\ 	ext{J mol}^{-1}\ 	ext{K}^{-1})$$

Accepted Answer

$$Q = 75.4 	imes 0.5 	imes 10 = 377\ 	ext{J}$$

Question 6

Which material listed in the table has the highest specific heat capacity?

Accepted Answer

Water (liquid)

Question 7

Why is it incorrect to ask 'How much heat is contained in this object?' according to the study materials?

Accepted Answer

Because heat refers to energy transfer, not a property of the system.

Question 8

Convert 100 calories to Joules. (1 cal = 4.184 J)

Accepted Answer

$$100 	imes 4.184 = 418.4\ 	ext{J}$$

Question 9

A 0.1 kg sample of copper is heated from 20°C to 50°C. How much heat is required? (Specific heat of copper $$c = 390\ 	ext{J kg}^{-1}\ 	ext{K}^{-1})$$

Accepted Answer

$$Q = 390 	imes 0.1 	imes 30 = 1,170\ 	ext{J}$$

Question 10

Which of the following best explains why water has an unusually high specific heat?

Accepted Answer

Water has special hydrogen bonding interactions.

Question 11

If you want to convert the specific heat capacity of a substance to its molar heat capacity, which equation should you use?

Accepted Answer

$$C = c 	imes M$$

Question 12

A 0.2 kg sample of aluminum is heated by 15 K. How much heat is required? (Specific heat of aluminum $$c = 910\ 	ext{J kg}^{-1}\ 	ext{K}^{-1})$$

Accepted Answer

$$Q = 910 	imes 0.2 	imes 15 = 2,730\ 	ext{J}$$

Question 13

Which of the following is NOT a correct unit for heat?

Accepted Answer

$$	ext{kg}$$

Question 14

A 0.05 kg sample of ethylene glycol is heated by 10 K. How much heat is required? (Specific heat of ethylene glycol $$c = 2386\ 	ext{J kg}^{-1}\ 	ext{K}^{-1})$$

Accepted Answer

$$Q = 2386 	imes 0.05 	imes 10 = 1,193\ 	ext{J}$$

Question 15

Which of the following statements is true regarding the relationship between heat and temperature?

Accepted Answer

Temperature can be changed by adding or removing heat from a system.

Question 16

A 0.1 kg sample of ice (near 0°C) is heated by 10 K. How much heat is required? (Specific heat of ice $$c = 2100\ 	ext{J kg}^{-1}\ 	ext{K}^{-1})$$

Accepted Answer

$$Q = 2100 	imes 0.1 	imes 10 = 2,100\ 	ext{J}$$

Question 17

Which of the following substances would require the least amount of heat to raise the temperature of 1 kg by 1 K?

Accepted Answer

Lead

Question 18

If you cut an object in half, what happens to its temperature according to the study materials?

Accepted Answer

The temperature of each half remains the same as the original object.

Question 19

Which of the following is a real-life application of the concept of heat capacity?

Accepted Answer

Using water as a coolant in car engines due to its high specific heat.

Heat, Heat Capacity, and Phase Changes

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