Chemistry-Chapter 2
The temperature at which water melts and freezes is the same.
TRUE
Water vapor is a gas.
TRUE
When a liquid is boiling, its temperature does not change.
TRUE
Which of the following is a physical change?
dry ice subliming
Raising the temperature of 10.0 g of water from 10.0 °C to 20.0 °C requires 100.0 cal of energy, while raising the temperature of 10.0 g of aluminum from 10.0 °C to 20.0 °C requires 22 cal. More calories are required to heat the water because
water has a larger specific heat than aluminum
Which of the following is an example of potential energy?
water stored in a reservoir
The lowest temperature on the Kelvin scale is __________ kelvin.
0 (zero)
A kilocalorie of heat is required to raise the temperature of
100 g of water by 10 °C
The nutritional calorie (Cal) is the same as __________ cal.
1000
The dietary calorie (Cal) is equal to
1000 calories
A patient has a temperature of 38.5 °C. What is the temperature in degrees Fahrenheit?
101.3 °F
A slice of pizza contains 29 g of carbohydrate, 13 g of protein and an unknown amount of fat. If the pizza contains 280 kcal, how many grams of fat are present? Report the answer to 2 significant figures.
12 g
The number of calories needed to raise the temperature of 32 g of water from 12 °C to 54 °C is
1300 cal
3.25 kcal is the same amount of energy as
13600 J
650. J is the same amount of energy as
155 cal
If the temperature is - 55 °C, what is the corresponding temperature on the Kelvin scale?
218 K
A serving of fish contains 50 g of protein and 4 g of fat. If protein has a caloric value of 4.0 kcal/g and fat has 9.1 kcal/g, how many kcal are in the serving? Report the answer to 2 significant figures.
240 kcal
One cup of kidney beans contains 15 g of protein, 1 g of fat, and 42 g of carbohydrate. How many kilocalories, to two significant figures, does this sample contain?
240 kcal
On a hot day, the thermometer read 95 °F. What is the temperature in degrees Celsius?
35 °C
A cheeseburger from a fast food restaurant contains 19 g of fat, 20 g of carbohydrate, and 28 g of protein. How many kcal of energy does the cheeseburger contain? (The accepted caloric values for foods are 4.0 kcal/g for carbohydrate, 9 kcal/g for fat, and 4 kcal/g for protein.) Report the answer to 2 significant figures.
360 kcal
How many calories are required to raise the temperature of a 35.0 g sample of iron from 25 °C to 35 °C? Iron has a specific heat of 0.108 cal/g °C.
38 cal
A diet has a total caloric intake of 1400 kcal. The diet consists of 50.% carbohydrate, 35% protein, and 15% fat. The number of kcal of protein in the diet is
490 kcal
A temperature of 41 °F is the same as
5 °C
A 2.5 g sample of french fries is placed in a calorimeter with 500.0 g of water at an initial temperature of 21 °C. After combustion of the french fries, the water has a temperature of 48 °C. What is the caloric value (kcal/g) of the french fries?
5.4 kcal/g
If the temperature is 20 °C, what is the corresponding temperature on the Fahrenheit scale?
68 °F
How many calories are required to raise the temperature of a 150. g sample of gold from 25 °C to 175 °C? The specific heat of gold is 0.0308 cal/g °C.
693 cal
The temperature of liquid nitrogen is - 196 °C. What is the corresponding reading on the Kelvin scale?
77 K
A potato contains 20 g of carbohydrate. If carbohydrate has a caloric value of 4 kcal/g, how many kcal are obtained from the carbohydrate in the potato?
80 kcal
How many calories are required to increase the temperature of 13 g of alcohol from 11 °C to 23 °C? The specific heat of alcohol is 0.588 cal/g °C.
92 cal
As heat is removed from a solid, its temperature decreases.
TRUE
Identify each of the following transformations as a chemical or physical change: a nail rusting
Chemical
Identify each of the following transformations as a chemical or physical change: baking a cake
Chemical
Identify each of the following transformations as a chemical or physical change: burning leaves
Chemical
Identify each of the following transformations as a chemical or physical change: formation of green leaves on a plant
Chemical
Identify each of the following transformations as a chemical or physical change: silver tarnishing
Chemical
Carbohydrates and proteins have the same caloric value per gram.
TRUE
Condensation occurs when a liquid is converted to a solid.
FALSE
Molecules of a gas are very close together.
FALSE
The units of specific heat are cal g/°F.
FALSE
Water freezes at 100 °C.
FALSE
Match the state of matter with each of the following descriptions of a substance. Solid? Liquid? Solid+Liquid? Liquid+Gas? Gas? - - Great distances exist between the particles.
Gas
Match the state of matter with each of the following descriptions of a substance. Solid? Liquid? Solid+Liquid? Liquid+Gas? Gas? - - Particles are held close together in a random pattern.
Liquid
Match the state of matter with each of the following descriptions of a substance. Solid? Liquid? Solid+Liquid? Liquid+Gas? Gas? - - This substance is boiling.
Liquid + Gas
Identify each of the following transformations as a chemical or physical change: a button falling off of a shirt
Physical
Identify each of the following transformations as a chemical or physical change: cutting the grass
Physical
Identify each of the following transformations as a chemical or physical change: melting ice
Physical
Identify each of the following transformations as a chemical or physical change: placing photographs in a scrapbook
Physical
Identify each of the following transformations as a chemical or physical change: water evaporating
Physical
Match the state of matter with each of the following descriptions of a substance. Solid? Liquid? Solid+Liquid? Liquid+Gas? Gas? - - This material has a definite volume, and a definite shape.
Solid
Match the state of matter with each of the following descriptions of a substance. Solid? Liquid? Solid+Liquid? Liquid+Gas? Gas? - - This substance is melting.
Solid + Liquid
A solid has a constant shape and volume.
TRUE
As a solid melts, its temperature does not change.
TRUE
Which of the following is a property of a solid?
The particles have fixed positions and are very close together
The specific heat of copper is 0.0920 cal/g °C, and the specific heat of silver is 0.0562 cal/g °C. If 100 cal of heat is added to one g of each metal at 25 °C, what is the expected result?
The silver will reach a higher temperature
Which of the following does NOT represent a step on the heating curve of water?
The temperature of steam cannot exceed 100 °C
Bromine (Br2) has a freezing point of -7 °C, and a boiling point of 60 °C.Indicate the state or change of state occurring at each temperature. 60 °C
boiling
Which of the following would NOT be a physical change?
burning gasoline in a lawnmower
Which of the following is a chemical change?
burning sugar
The units of specific heat are __________.
cal/g °C or J/g °C
Gold in a wedding ring is a(n)
element
Helium is a(n)
element
The simplest type of pure substance is an __________.
element
The primary substances of which all other things are composed are
elements
The phrase "ability to do work" is a definition of
energy
The formation of a gas resulting from the escape of high-energy particles from the surface of a liquid is known as
evaporation
When a liquid boils, the process by which the molecules leave its surface is called __________.
evaporation
Bromine (Br2) has a freezing point of -7 °C, and a boiling point of 60 °C.Indicate the state or change of state occurring at each temperature. 70 °C
gas
Which of the following is an example of a physical change?
grinding coffee beans
Which of the following is a physical property of both liquids and gases?
has randomly arranged particles
The energy associated with the motion of particles in a substance is called
heat
Coins in a piggy bank is a(n)
heterogeneous mixture
Will the caloric value of a 100. g hamburger be higher or lower than the caloric value of 100. g of sugar?
higher
A mixture which has uniform properties is a __________ mixture.
homogeneous
Air is a(n)
homogeneous mixture
The energy of motion is called __________ energy.
kinetic
The energy of motion is referred to as
kinetic energy
Bromine (Br2) has a freezing point of -7 °C, and a boiling point of 60 °C.Indicate the state or change of state occurring at each temperature. 30 °C
liquid
Will the caloric value of a 100.g hamburger be higher or lower than the caloric value of 100. g of cooking oil?
lower
Bromine (Br2) has a freezing point of -7 °C, and a boiling point of 60 °C.Indicate the state or change of state occurring at each temperature. -7 °C
melting
Global warming is believed to result from all of the following except
movement of the Earth closer to the Sun
Which one of the following properties describes a liquid?
particles are close together and move randomly
The energy stored in the chemical bonds of a carbohydrate molecule is
potential energy
Which of the following does NOT involve a change of state?
pouring water into a vacuum-insulated bottle
The specific heat of a substance is the amount of heat needed to
raise the temperature of 1 g of the substance by 1 °C
An example of kinetic energy is
running water
Bromine (Br2) has a freezing point of -7 °C, and a boiling point of 60 °C.Indicate the state or change of state occurring at each temperature. -15 °C
solid
The physical state(s) present when a substance is melting is (are)
solid + liquid
In which of the following would the particles move most rapidly?
steam at 110 °C
The change of state from solid to gas is termed __________.
sublimation
When a solid is converted directly to a gas, the change of state is called
sublimation
A heating curve illustrates
the changes in the temperature and physical state of a substance as it is heated
Absolute zero is
the coldest temperature possible
A burn from steam at 100 °C is expected to be more severe than a burn from boiling water at 100 °C because
the steam will give off a large amount of heat as it condenses
In a gas, the distance between the particles is
very large relative to the size of the molecules