5.1 Energy Basics

Heat, thermal energy, and temperature kept distinct, with specific heat and heat capacity used to compute the energy behind a temperature change.

Chemistry 2e, 5.1 Energy Basics

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7 exercises

5.1 Exercise 1

A burning match and a bonfire may have the same temperature, yet you would not sit around a burning match on a fall evening to stay warm. Why not?

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5.1 Exercise 3

Explain the difference between heat capacity and specific heat of a substance.

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5.1 Exercise 5

Calculate the heat capacity, in joules and in calories per degree, of the following:

(a) 45.8 g of nitrogen gas

(b) 1.00 pound of aluminum metal

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5.1 Exercise 7

How much heat, in joules and in calories, is required to heat a 28.4-g (1-oz) ice cube from −23.0 °C to −1.0 °C?

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5.1 Exercise 9

If 14.5 kJ of heat were added to 485 g of liquid water, how much would its temperature increase?

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5.1 Exercise 11

A piece of unknown solid substance weighs 437.2 g, and requires 8460 J to increase its temperature from 19.3 °C to 68.9 °C.

(a) What is the specific heat of the substance?

(b) If it is one of the substances found in the table, what is its likely identity?

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5.1 Exercise 13

Most people find waterbeds uncomfortable unless the water temperature is maintained at about 85 °F. Unless it is heated, a waterbed that contains 892 L of water cools from 85 °F to 72 °F in 24 hours. Estimate the amount of electrical energy required over 24 hours, in kWh, to keep the bed from cooling. Note that 1 kilowatt-hour (kWh) = 3.6 $\times$ 10⁶ J, and assume that the density of water is 1.0 g/mL (…

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