SCI 105 Chapter 6
To say that water has a high specific heat capacity is to say that water
- absorbs a lot of energy for an increase in temperature - requires a lot of energy for an increase in temperature - releases a lot of energy in cooling.
The lowest possible temperature is
-273 C
Absolute zero corresponds to a temperature of
0 K and -273 C
Which of these involves the most thermal energy: 1 calorie, 1 Calorie, or 1 joule?
1 Calorie
The temperature of boiling water is
100 degrees c and 212 degrees f
The temperature of melting ice is
32°F and 0°C
Under what condition does a thermometer measure the temperature of its surroundings? (Why do we say that "a thermometer measures its own temperature"?)
A thermometer measures the temperature of its surroundings when the it has reached equilibrium at the temperature of its surroundings.
The final temperature of 1 liter of 40°C water poured into 1 liter of 20°C water is
At or about 30 degrees celsius
On which temperature scale is 0 degrees the freezing point of water?
Celsius
On which temperature scale is 212 degrees the boiling point of water?
F
The law of thermodynamics that consists of conservation of energy applied to thermal systems
First Law
Cite a way in which the energy value of foods is determined.
Food is chemically analyzed.
Suppose that we replace the aluminum with a mystery metal and repeat the experiment in the video. As in the video, the mass of the metal is the same as that of the water. Room temperature is about 20∘C∘C before the start of the experiment. The water heats up to 40∘C∘C, and the mystery metal heats up to 80∘C∘C. Compared to that of water, the heat capacity of our mystery metal is
Given the same input of energy, the temperature of the metal increased three times as much as the temperature of the water. Therefore, the metal has one-third the heat capacity of water. (Recall that the heat QQ delivered to a substance can be written QQ = mc ΔTmc ΔDeltaT, where mm is the mass of the substance and cc is its heat capacity.)
How does heat differ from thermal energy?
Heat is thermal energy in motion
Compared to a giant iceberg, a hot cup of coffee has
Higher temperature, but less thermal energy
What is the reason for ice being less dense than water?
Ice crystallizes with an open structure.
Which contracts more when the temperature is slightly increased? Equal volumes of
Ice water
Which of the following normally warms up faster when heat is applied?
Iron
Whether one object is warmer than another object has most to do with molecular
Kinetic energy
If a room is cold it is due to a
Lack of adequate thermal energy
When work is done on a system while additional heat is subtracted, the temperature of the system
Need more info
Heat is thermal energy that flows due to
Temperature differences
On which temperature scale does the average kinetic energy of molecules double when the temperature doubles?
The Kelvin temperature scale.
Consider two glasses, one filled with water and the other half-full, both at the same temperature. In which glass are the water molecules moving faster? In which is there greater thermal energy? In which will more heat be required to increase the temperature by 1∘C∘C?
The average speed of both is the same. The full glass has a greater thermal energy. More heat will be required to increase the temperature of the full glass by 1 Celcius degree, twice as much.
Does a hot object contain thermal energy or does it contain heat?
Thermal energy
Part complete Which of the following changes would make the water balloon more likely to pop? (Ignore effects of convection within the fluid.)
Using a liquid with a lower heat capacity than water means that the candle flame will raise the liquid's temperature more quickly than for water. A thicker balloon will conduct heat through to the liquid more slowly, so that the outer part of the balloon wall will heat up more quickly to its melting point.
How does the specific heat capacity of water compare with the specific heat capacities of other common materials?
Water has a higher specific heat capacity than other common materials.
The rock-bottom coldest an object can hope to reach is _______.
absolute zero/-273°C
Temperature is generally proportional to a substance's _____
average translational kinetic energy of its particles
Is the temperature of an object a measure of the total translational kinetic energy of molecules in the object or a measure of the average translational kinetic energy per molecule in the object?
average translational kinetic energy per molecule
If water at 0°C slightly increases in temperature, the water
contracts
When most substances are heated, molecules inside move faster and occupy more space, which results in thermal
expansion
Rank them from fastest to slowest in how quickly each warms up: (a) aluminum, 910 J/kg⋅∘CJ/kg⋅∘C ; (b) copper, 390 J/kg⋅∘CJ/kg⋅∘C ; (c) lead, 130 J/kg⋅∘CJ/kg⋅∘C .
fastest to slowest: CBA
What are the temperatures for freezing water on the Celsius and the Fahrenheit scales, respectively? For boiling water?
freezing water 0∘C, 32∘F; boiling water 100∘C, 212∘F
When you touch a piece of ice with your finger, energy flows
from your finger to the ice.
Rank the magnitudes of these units of thermal energy from greatest to least: (a) 1 calorie, (b) 1 Calorie, (c) 5 joule.
greatest to least: BCA
Which contracts more when the temperature is decreased? Equal volumes of
helium
Which expands more when the temperature is increased? Equal volumes of
helium
The moderate temperatures of islands throughout the world has mainly to do with water's
high specific heat capacity.
Heat is thermal energy that flows from
hot to cold
When work is done on a system and no heat is added, the temperature of the system
increases
Heat energy is measured in units of
joules and calories
A substance that heats up relatively quickly has a
low specific heat capacity
A substance that heats up relatively quickly has a
low specific heat capacity.
At absolute zero, a substance has
no more energy to give up
The open spaces in the crystal lattice of ice contain
nothing
Which law of thermodynamics addresses the direction of heat flow?
second law
Which will cool faster when removed from a furnace?
silver
Heat is
thermal energy flowing from hot to cold
Heat is simply another word for _______.
thermal energy that flows from hot to cold
When you place a sealed can of air on a hot stove burner, the can undergoes an increase in
thermal energy, temperature, pressure
The fact that a thermometer "takes its own temperature" illustrates
thermal equilibrium
The motion of atoms and molecules that most affects temperature is
translational
Part complete If the same quantity of heat is added to both a 1-liter and a 2-liter container of water, the temperature change of water in the 1-liter container will be
twice
When a gas such as helium becomes twice as hot it has
twice the thermal energy and twice the absolute temperature
The motion of particles that contribute to thermal energy are
vibrational, rotational, translational.
During a very cold winter, water pipes sometimes burst because
water expands when freezing.