Chemistry Chapter 2 Questions

What must occur in a substance in order to determine a chemical property?

A chemical property can be determined only when a change in the substance occurs in the presence of another substance or when sufficient energy of some form is added to it.

What is a physical change? Give three examples of physical changes.

A physical change results only in a rearrangement of the particles of matter, not in their composition. Examples include crushing, dissolving, hammering into a thin sheet, or changing state. (§2.3)

Differentiate between physical and chemical properties of matter. Give two examples of each property.

A physical property of matter can be determined or observed without altering the chemical composition of the matter. Examples include color, hardness, electrical conductivity and malleability. A chemical property can be determined only through a change to the material that permanently alters its composition. Examples include combustion in the presence of oxygen and decomposition in the presence of an electrical current.

5. Tell whether each of the following processes involves a physical change, a chemical change or both. a. a wafer of silicon being scored and cut into chips to be used in computer microprocessors b. a glacier melting c. small water droplets forming on the outside surface of a cold can of soft drink d. dynamite exploding and the resulting collapse of an old building e. a burning candlewick melting wax f. the rusting of spokes on a bicycle's wheels g. the growth of a child h. the erosion of a hillside

A. physical change b.physical change c.physical change d.chemical change e.chemical change and physical change f.chemical change g.chemical change h.physical change

How does an ion differ from an atom?

An ion is a charged atom in which there is a mismatch of electrons and protons. An atom is assumed to be uncharged.

State three evidences that the particles of substance are in continuous motion.

Answers will vary. Diffusion of perfume odors in air, evaporation of steam droplets in air, and Brownian motion in microscopic objects. (§2.12)

Discuss why temperature is the most important factor in determining the state of a substance.

Answers will vary. Students should note the relationship between particle kinetic energy and substance temperature, particle motion in relation to attractive forces between particles, and distance of particles that determine the phase of the substance. (§2.14)

Compare and contrast gases and plasmas.

Both gases and plasmas consist of energetic particles that are so far apart that attractive forces between particles are inconsequential. They are both highly compressible, have no definite volume, and can diffuse to occupy a volume of space. In contrast, gases consist of intact atoms or molecules, while the particle in plasmas are mostly ions and free electrons. The temperature of plasmas are usually several orders of magnitude higher than that of gases.

During what meteorological (weather) changes does deposition occur on earth?

Deposition occurs whenever frost or snowflakes form. These are very common processes over much of the earth's surface.

Is energy something a system does or something it has?

Energy is something a system has. The energy of a system consists of the motion of a system's particles as well as the motion of the system as a whole. If the system transfers its energy to something else, it does work. (§2.9)

(True / False) The modern system of chemical symbols was developed by John Dalton in the early 1800s.

False. The modern system of chemical symbols was developed by Hons Berzelius.

(True / False) The belief that space dust can spontaneous come together to form a planet is a good example of the second law of thermodynamics.

False. The probability of such an event happening is so remote that is considered impossible. The structure of a planet represents a much higher level of orderliness than the random arrangement of dust particles in space.

(True / False) The origin of matter and energy in the universe by naturalistic processes is an established fact beyond scientific debate.

False. Theories of the origins of matter and energy are firmly linked to one's presupposition about the existence of a Creator or the power of inanimate matter to evolve.

(True / False) The thermal energy of a system is determined by the formula E = mc

False. This famous equation from Einstein's special theory of relativity quantifies how much energy could be obtained if a certain amount of mater were converted to pure energy. It shows the equivalence of energy and matter.

Explain the difference between heterogeneous and homogeneous mixtures.

Heterogeneous mixtures consist of two or more materials segregated into distinct pieces, regions, or phases (e.g. granite). A homogeneous mixture is a physical combination of two or more pure substances where the individual particles of the substances are uniformly distributed throughout the mixture (e.g. salt water). (§2.5)

Since heat transfers only take place between systems with different temperatures, explain why the third law of thermodynamics is support by our current understanding of matter.

In order to cool a point to absolute zero, the thermal energy in the particles at that point would have to flow to a colder spot, which is impossible, since there is no point colder than absolute zero by definition.

How is shot peening an example of using technology to exercise dominion and to love your neighbor as yourself

Loss of life and expense as well as exploitation of the natural resource God has given us can all be avoided with a process like shot or laser peening. (§§2.3-2.4)

What is matter and where did it come from?

Matter is anything that occupies space and has mass. All matter was created during the events of Creation Week when it was spoken into existence by God.

State the operational descriptions of matter and energy

Matter is anything that occupies space and has mass. Energy is the ability to do work.

What condition distinguishes plasmas from more "normal" states of matter?

Plasmas occur only at extremely high temperatures (defined by the energy of the individual particles).

List the known states of matter in order form the most energetic to the least.

Quark-gluon plasma, plasma, gas, liquid, solid, Bose-Einstein condensate. (§2.14, facet)

What property of metal does shot peening use?

Shot peening uses the malleability of metal to increase its strength. (§§2.3-2.4)

Compare the entropy of a firecracker before it is lighted to its entropy after it explodes. Explain the difference.

The firecracker's entropy after it has burst is greater than before it is lighted. The firecracker has less usable energy and its parts are more disorganized (less ordered) after it explodes. (§2.11)

State the first law of thermodynamics. What does this law imply for the origins of matter and energy?

The first law states that energy and matter can neither be created nor destroyed, only converted form one form to another. It implies that, barring miracles, there must have been a beginning of creation to account for both the energy and matter in the universe.

Why is the joule the preferred unit of energy in scientific studies? What part of the definition of the calorie could make it more convenient for use in non-scientific studies?

The joule is the SI unit for any form of energy, which is derived from fundamental SI units. The joule is not restricted to a particular kind of energy. The calorie is defined as the heat transfer required to change the temperature of 1 g of water 1 ° C. These are easily measured units for many kinds of work.

Describe the two kinds of pure substances. How do these differ from mixtures?

The particles in pure substances consist of all one kind of atom (a single element) or those that make up only one compound. Pure substances differ from mixtures in that mixtures are combinations of two or more substances that are not chemically combined.

Why are solids and liquids relatively incompressible?

The particles in solids and liquids are so close together that they cannot be squeezed any closer. The structure of atoms prevents two atoms from occupying the same space at the same time

Why is creation ex nihilo a religious belief and not a scientfic fact?

The special creation of the universe and everything in it was not and is not observable by humans, and is therefore outside the realm of observational science. To accept the declarations of Scripture must be done in faith, which is one of the foundations of Christianity.

Explain the difference between temperature and thermal energy.

The thermal energy contained in a system is the total kinetic energy of the particles in the system. Temperature is a property that is proportional to the average kinetic energy of the system's particles. Thermal energy is related to the quantity of matter present; temperature is not. (§2.12)

When you grasp a hot cup of cocoa with cold hands, which way does the heat transfer occur? Explain

The thermal energy flows from the hot cup into the cold hands until they are the same temperature. Heat transfers always occur from higher temperature to lower temperatures according to the second law of thermodynamics.

What are the two main classes of matter and what characteristics differentiate them?

The two main classes of matter are pure substances and mixtures. A pure substance consists of only one kid of matter that is chemically combined (an element or a compound). A mixture is a physical combination of two or more substances. (§2.5)

Why do some chemical symbols for elements consist of two letters and other of only one?

There are more elements than letters of the alphabet, so some symbols must use two letters to prevent confusion between elements. Because some elements begin with the same letter, a second letter is added to discriminate them.

What specifically does thermodynamics investigate? What invention spurred its development?

Thermodynamics is the study of the movement and conversion of energy. The area developed as a result of the invention of the steam engine.

What kind of change does shot peening cause in a sheet of metal? Why is it that type of change?

This is an example of a physical change because the substance is not changed. (§§2.3-2.4)

(True / False) A chemical property of a substance cannot be determined without causing or attempting to cause a chemical change to occur in the substance.

True

(True / False) A solution, such as filtered air, is a homogeneous mixture.

True

(True / False) Absolute zero cannot be reached at a given location because there cannot be a colder place where thermal energy can flow to in order to cool the location.

True

(True / False) In order to be useful, energy must often be converted from one form to another.

True

(True / False) One of the difficulties with the big bang origin of the universe is that many evidence predicted by the theory are not seen in the universe today or are contradict by other evidence.

True

(True / False) Thermal energy, unlike internal energy, does not account for the potential energies of the particles in a system.

True

(True or False) Liquids flow only when a force acts on them.

True

(True or False) Molecules consisting of two or more elements are the smallest identifiable particles of noncrystalline compounds

True

The melting point is identical to the freezing point of a substance.

True

Convert the following temperature from the Kelvin to the Celsius Scales. a. 496 K (temperature of rock at 5.9 km depth) b. 2.726 K (average temperature of deep space) c. 1783 K (melting point of steel) d. 273.16 K (triple point of water)

a. 223 °C b. -270.42 °C c. 1510 °C d. 0.01 °C (§2.13)

Convert the following temperatures from Celsius to Kelvin scales. Express your answers to the nearest hundredth of a degree a. 0.00 °C (freezing point of water) b. 22.22 °C (room temperature) c. 100.00 °C (boiling point of water) d. -218.30 °C (melting point of oxygen)

a. 273.15 K b. 295.37 K c. 373.15 K d. 54.85 K (§2.13)

Name the principal type of energy involved in each of the following: a. vibrations from a loudspeaker b. a pot of near-boiling water c. a camera flash d. the source of an explosion of dynamite e. changes occurring at the center of a star f. a rolling ball

a. acoustic or sound energy b. thermal energy c. electromagnetic energy d. chemical energy e. nuclear energy f. mechanical (kinetic) energy (§2.9)

For each of the following elements, give the term that best describes how its atoms exist under "normal" conditions. Be as specific as possible. For example, N2 would be a diatomic element. a. oxygen (O2) b. red phosphorus (P4) c. sulfur (S8) d. helium (He)

a. diatomic element b. polyatomic element c. polyatomic element d. monatomic element (§2.6)

Classify each of the following as elements or compounds. Assuming these substances all consist of particle, describe the particle as completely as possible. a. oxygen (O2) b. carbon monoxide (CO) c. ozone (O3) d. helium (He) e. methane (CH4) f. hydrogen peroxide (H2O2)

a. element; diatomic molecule b.compound; molecule c.element; polyatomic molecule d.element; atom e.compound; molecules f. compound;molecules

Name the changes of state that are described by the following processes. a. Pond water solidifies on a cold winter day. b. The fragrance of an open perfume bottle is smelled from across the room. c. Water leaves a teakettle that is sitting on a hot stove. d. Frost patterns appear on a cold window pane in winter. e. Water mist collects on the bathroom mirror after a shower. f. You smell the odor of moth balls when you open a clothes box. g. As a candle burns, wax drips down the sides of the candle.

a. freezing b. vaporization c. vaporization d. deposition e. condensation f. sublimation g. melting (§2.15)

Use the classification scheme of matter presented in this chapter to classify the following substances as elements, compound, homogeneous mixtures, or heterogeneous mixtures. Assume the substances are uncontaminated. Example. Magnesium sulfate (MgSO4) is a compound. a. vegetable soup b. air c. oxygen (O2) d. gasoline e. sulfuric acid (H2SO4) f. granite

a. heterogeneous mixture b. homogeneous mixture c. element d. homogeneous mixture e. compound f. heterogeneous mixture

What principal form of energy is involved in the following processes? a. energy that heats the water in the core of a nuclear power plant reactor b. energy that activates the digital display of a cell phone c. energy possessed by a bat striking a baseball d. energy received by a digital camera through its lens e. energy released during the digestion process f. energy used by refrigerator magnets

a. nuclear b. electromagnetic (electrical) c. mechanical (kinetic) d. electromagnetic (light) e. chemical f. electromagnetic (magnetism)

Tell whether each of the following properties is a physical property or a chemical property. a. color b.density c.insulting ability d. acidity e. magnetism f. flammability

a. physical b.physical c.physical d.chemical e.physical f.chemical

Give the number of each kind of atom in the following formula units or molecules. a. 5NaCl b. Ca(OH)2 c. HC2H3O2 d. 4Li2O

a.) five Na, five Cl b.) one Ca, two O, two H c.) four H, two C, two O d.) eight Li, four O (§2.7)

The ides of mean are not always in harmony with the way the universe operates. Identify the laws that says that each of the following is impossible. a. A perpetual motion machine, once started with an initial input of energy, continues running indefinitely b. A machine produces more energy than it consumes c. The universe spontaneously came into existence. d. Organisms with new structural features descended from those without the genetic information for those features.

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