Which Statement Describes an Intensive Property of Matter

1.three Physical and Chemical Properties

Learning Objectives

By the end of this section, y’all will exist able to:

  • Identify backdrop of and changes in matter as physical or chemical
  • Identify properties of matter as extensive or intensive

The characteristics that enable us to distinguish one substance from another are called properties. A
physical property
is a characteristic of matter that is not associated with a change in its chemical composition. Familiar examples of concrete properties include density, colour, hardness, melting and humid points, and electrical electrical conductivity. Nosotros can observe some physical properties, such as density and color, without irresolute the physical state of the matter observed. Other physical properties, such as the melting temperature of iron or the freezing temperature of water, can only be observed as matter undergoes a physical modify. A
physical change
is a alter in the country or backdrop of affair without any accompanying modify in its chemical composition (the identities of the substances independent in the matter). We discover a physical alter when wax melts, when sugar dissolves in java, and when steam condenses into liquid water (Figure 1). Other examples of concrete changes include magnetizing and demagnetizing metals (as is done with common antitheft security tags) and grinding solids into powders (which tin sometimes yield noticeable changes in colour). In each of these examples, there is a modify in the concrete state, class, or properties of the substance, but no change in its chemical composition.

Figure one.
(a) Wax undergoes a concrete alter when solid wax is heated and forms liquid wax. (b) Steam condensing inside a cooking pot is a concrete change, as water vapor is changed into liquid water. (credit a: modification of piece of work by “95jb14”/Wikimedia Commons; credit b: modification of work by “mjneuby”/Flickr)

The alter of one type of matter into another type (or the disability to change) is a
chemical property. Examples of chemic properties include flammability, toxicity, acidity, reactivity (many types), and oestrus of combustion. Fe, for example, combines with oxygen in the presence of h2o to course rust; chromium does not oxidize (Effigy ii). Nitroglycerin is very dangerous because information technology explodes easily; neon poses almost no adventure because information technology is very unreactive.

Figure A is a photo of metal machinery that is now mostly covered with reddish orange rust. Figure B shows the silver colored chrome parts of a motorcycle. One of the parts is so shiny that you can see a reflection of the surrounding street and buildings.
Figure two.
(a) I of the chemical backdrop of iron is that it rusts; (b) 1 of the chemical properties of chromium is that it does not. (credit a: modification of work by Tony Hisgett; credit b: modification of work past “Atoma”/Wikimedia Commons)

To identify a chemic property, we look for a chemical change. A
chemical change
always produces one or more types of matter that differ from the matter sspresent before the modify. The formation of rust is a chemical change because rust is a different kind of matter than the iron, oxygen, and h2o present before the rust formed. The explosion of nitroglycerin is a chemical change because the gases produced are very different kinds of matter from the original substance. Other examples of chemical changes include reactions that are performed in a lab (such as copper reacting with nitric acrid), all forms of combustion (called-for), and nutrient being cooked, digested, or rotting (Figure iii).

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Figure A is a photo of the flask containing a blue liquid. Several strands of brownish copper are immersed into the blue liquid. There is a brownish gas rising from the liquid and filling the upper part of the flask. Figure B shows a burning match. Figure C shows red meat being cooked in a pan. Figure D shows a small bunch of yellow bananas that have many black spots.
Figure 3.
(a) Copper and nitric acid undergo a chemical alter to grade copper nitrate and brown, gaseous nitrogen dioxide. (b) During the combustion of a match, cellulose in the match and oxygen from the air undergo a chemic modify to form carbon dioxide and water vapor. (c) Cooking red meat causes a number of chemical changes, including the oxidation of iron in myoglobin that results in the familiar ruby-to-brown color change. (d) A assistant turning brownish is a chemical change equally new, darker (and less tasty) substances form. (credit b: modification of work past Jeff Turner; credit c: modification of work by Gloria Cabada-Leman; credit d: modification of work by Roberto Verzo)

Properties of matter fall into one of two categories. If the property depends on the corporeality of matter present, information technology is an
extensive belongings. The mass and volume of a substance are examples of extensive backdrop; for instance, a gallon of milk has a larger mass and book than a cup of milk. The value of an extensive property is direct proportional to the amount of matter in question. If the property of a sample of thing does not depend on the amount of affair nowadays, information technology is an
intensive belongings. Temperature is an case of an intensive property. If the gallon and cup of milk are each at 20 °C (room temperature), when they are combined, the temperature remains at 20 °C. Equally another example, consider the distinct but related backdrop of heat and temperature. A drop of hot cooking oil spattered on your arm causes brief, minor discomfort, whereas a pot of hot oil yields severe burns. Both the driblet and the pot of oil are at the same temperature (an intensive property), but the pot clearly contains much more than heat (extensive holding).

Hazard Diamond

You may have seen the symbol shown in Figure iv on containers of chemicals in a laboratory or workplace. Sometimes called a “burn down diamond” or “gamble diamond,” this chemic run a risk diamond provides valuable information that briefly summarizes the various dangers of which to be aware when working with a particular substance.

The diamond is subdivided into four smaller diamonds. The upper diamond is colored red and is associated with fire hazards. The numbers in the fire hazard diamond range from 0 to 4. As the numbers increase, the chemical’s flash point decreases. 0 indicates a substance that will not burn, 1 indicates a substance with a flashpoint above 200 degrees Fahrenheit, 2 indicates a substance with a flashpoint above 100 degrees Fahrenheit and not exceeding 200 degrees Fahrenheit, 3 indicates a substance with a flashpoint below 100 degrees Fahrenheit, and 4 indicates a substance with a flashpoint below 73 degrees Fahrenheit. The right-hand diamond is yellow and is associated with reactivity. The reactivity numbers range from 0 to 4. 0 indicates a stable chemical, 1 indicates a chemical that is unstable if heated, 2 indicates the possibility of a violent chemical change, 3 indicates that shock and heat may detonate the chemical and 4 indicates that the chemical may detonate. The lower diamond is white and is associated with specific hazards. These contain abbreviations that describe specific hazardous characteristic of the chemical. O X indicates an oxidizer, A C I D indicates an acid, A L K indicates an alkali, C O R indicates corrosive, a W with a line through it indicates use no water, and a symbol of a dot surrounded by three triangles indicates radioactive. The leftmost diamond is blue and is associated with health hazards. The numbers in the health hazard diamond range from 0 to 4. 0 indicates a normal material, 1 indicates slightly hazardous, 2 indicates hazardous, 3 indicates extreme danger, and 4 indicates deadly.
Effigy 4.
The National Fire Protection Agency (NFPA) risk diamond summarizes the major hazards of a chemical substance.

The National Fire Protection Agency (NFPA) 704 Hazard Identification Arrangement was developed by NFPA to provide safety information almost certain substances. The arrangement details flammability, reactivity, wellness, and other hazards. Within the overall diamond symbol, the pinnacle (cherry) diamond specifies the level of fire hazard (temperature range for flash betoken). The blue (left) diamond indicates the level of wellness hazard. The yellowish (right) diamond describes reactivity hazards, such equally how readily the substance will undergo detonation or a violent chemical alter. The white (bottom) diamond points out special hazards, such as if it is an oxidizer (which allows the substance to burn in the absence of air/oxygen), undergoes an unusual or dangerous reaction with water, is corrosive, acidic, alkaline, a biological run a risk, radioactive, and and then on. Each adventure is rated on a scale from 0 to four, with 0 existence no hazard and 4 being extremely chancy.

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While many elements differ dramatically in their chemical and physical properties, some elements have similar backdrop. Nosotros can place sets of elements that showroom mutual behaviors. For example, many elements conduct heat and electricity well, whereas others are poor conductors. These properties can be used to sort the elements into three classes: metals (elements that behave well), nonmetals (elements that conduct poorly), and metalloids (elements that have properties of both metals and nonmetals).

The periodic table is a table of elements that places elements with similar backdrop close together (Figure 4). Yous volition learn more than about the periodic tabular array as you continue your study of chemistry.

On this depiction of the periodic table, the metals are indicated with a yellow color and dominate the left two thirds of the periodic table. The nonmetals are colored peach and are largely confined to the upper right area of the table, with the exception of hydrogen, H, which is located in the extreme upper left of the table. The metalloids are colored purple and form a diagonal border between the metal and nonmetal areas of the table. Group 13 contains both metals and metalloids. Group 17 contains both nonmetals and metalloids. Groups 14 through 16 contain at least one representative of a metal, a metalloid, and a nonmetal. A key shows that, at room temperature, metals are solids, metalloids are liquids, and nonmetals are gases.
Figure 4.
The periodic table shows how elements may exist grouped according to certain like properties. Annotation the background colour denotes whether an element is a metal, metalloid, or nonmetal, whereas the element symbol color indicates whether it is a solid, liquid, or gas.

Key Concepts and Summary

All substances have distinct physical and chemic properties, and may undergo concrete or chemic changes. Physical properties, such as hardness and boiling point, and concrete changes, such as melting or freezing, exercise not involve a change in the limerick of thing. Chemic properties, such flammability and acidity, and chemical changes, such every bit rusting, involve production of matter that differs from that present beforehand.

Measurable properties fall into ane of two categories. All-encompassing backdrop depend on the corporeality of matter present, for example, the mass of gilt. Intensive backdrop practice not depend on the amount of thing present, for example, the density of aureate. Oestrus is an example of an extensive property, and temperature is an case of an intensive property.

Chemistry End of Chapter Exercises

  1. Classify the six underlined properties in the post-obit paragraph as chemical or physical:

    Fluorine is a stake yellow
    gas
    that
    reacts with most substances. The complimentary element
    melts at −220 °C
    and
    boils at −188 °C. Finely divided
    metals burn down in fluorine
    with a brilliant flame.
    Nineteen grams of fluorine volition react with one.0 gram of hydrogen.

  2. Classify each of the post-obit changes as physical or chemical:

    (a) condensation of steam

    (b) burning of gasoline

    (c) souring of milk

    (d) dissolving of sugar in water

    (e) melting of gold

  3. Classify each of the following changes as concrete or chemical:

    (a) coal burning

    (b) ice melting

    (c) mixing chocolate syrup with milk

    (d) explosion of a firecracker

    (e) magnetizing of a screwdriver

  4. The book of a sample of oxygen gas inverse from x mL to 11 mL as the temperature inverse. Is this a chemic or physical change?
  5. A 2.0-liter volume of hydrogen gas combined with 1.0 liter of oxygen gas to produce 2.0 liters of water vapor. Does oxygen undergo a chemical or physical change?
  6. Explain the difference between extensive properties and intensive properties.
  7. Place the following properties equally either extensive or intensive.

    (a) volume

    (b) temperature

    (c) humidity

    (d) oestrus

    (due east) boiling point

  8. The density (d) of a substance is an intensive property that is defined every bit the ratio of its mass (m) to its volume (V).

    [latex]\text{density}= \frac{\text{mass}}{\text{volume}}[/latex] [latex]\text{d} = \frac{\text{m}}{\text{V}}[/latex]

    Considering that mass and volume are both extensive properties, explain why their ratio, density, is intensive.

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Glossary

chemical change
alter producing a different kind of matter from the original kind of affair
chemical property
beliefs that is related to the modify of i kind of thing into another kind of thing
extensive holding
property of a substance that depends on the amount of the substance
intensive holding
belongings of a substance that is independent of the amount of the substance
physical modify
change in the state or properties of matter that does not involve a change in its chemical composition
physical property
characteristic of matter that is not associated with any change in its chemic composition

Solutions

Answers for Chemistry Finish of Affiliate Exercises

2. (a) physical; (b) chemical; (c) chemical; (d) physical; (e) physical

4. physical

6. The value of an extensive holding depends upon the amount of matter existence considered, whereas the value of an intensive property is the same regardless of the corporeality of matter being considered.

8. Being extensive backdrop, both mass and volume are directly proportional to the amount of substance nether study. Dividing one extensive belongings by another volition in outcome “cancel” this dependence on corporeality, yielding a ratio that is independent of corporeality (an intensive holding).

Which Statement Describes an Intensive Property of Matter

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