Chapter 1 1.6 to 1.9 Chemical Foundations

1.9 Classification of Matter Chapter 1 Table of Contents 1.6 Dimensional Analysis 1.7 Temperature 1.8 Density 1.9 Classification of Matter Return to TOC Copyright © Cengage Learning. All rights reserved

Section 1.6 Dimensional Analysis Use when converting a given result from one system of units to another. To convert from one unit to another, use the equivalence statement that relates the two units. Derive the appropriate unit factor by looking at the direction of the required change (to cancel the unwanted units). Multiply the quantity to be converted by the unit factor to give the quantity with the desired units. Copyright © Cengage Learning. All rights reserved

The two unit factors are: Section 1.6 Dimensional Analysis Example #1 A golfer putted a golf ball 6.8 ft across a green. How many inches does this represent? To convert from one unit to another, use the equivalence statement that relates the two units. 1 ft = 12 in The two unit factors are: Copyright © Cengage Learning. All rights reserved

Dimensional Analysis Example #1 Section 1.6 Example #1 Dimensional Analysis A golfer putted a golf ball 6.8 ft across a green. How many inches does this represent? Derive the appropriate unit factor by looking at the direction of the required change (to cancel the unwanted units). Copyright © Cengage Learning. All rights reserved

Dimensional Analysis Example #1 Section 1.6 Example #1 Dimensional Analysis A golfer putted a golf ball 6.8 ft across a green. How many inches does this represent? Multiply the quantity to be converted by the unit factor to give the quantity with the desired units. Copyright © Cengage Learning. All rights reserved

Dimensional Analysis Example #2 Section 1.6 Dimensional Analysis Example #2 An iron sample has a mass of 4.50 lb. What is the mass of this sample in grams? (1 kg = 2.2046 lbs; 1 kg = 1000 g) Copyright © Cengage Learning. All rights reserved

React 3 What data would you need to estimate the money you would spend on gasoline to drive your car from New York to Chicago? Provide estimates of values and a sample calculation. Copyright © Houghton Mifflin Company. All rights reserved. 1–26

Dimensional Analysis Concept Check Section 1.6 Dimensional Analysis Concept Check What data would you need to estimate the money you would spend on gasoline to drive your car from New York to Los Angeles? Provide estimates of values and a sample calculation. This problem requires that the students think about how they will solve the problem before they can plug numbers into an equation. A sample answer is: Distance between New York and Los Angeles: 3200 miles Average gas mileage: 25 miles per gallon Average cost of gasoline: $2.75 per gallon (3200 mi) × (1 gal/25 mi) × ($2.75/1 gal) = $352 Total cost = $350 Copyright © Cengage Learning. All rights reserved

Examples Because you never learned dimensional analysis, you have been working at a fast food restaurant for the past 35 years wrapping hamburgers. Each hour you wrap 184 hamburgers. You work 8 hours per day. You work 5 days a week. you get paid every 2 weeks with a salary of $840.34. How many hamburgers will you have to wrap to make your first one million dollars?

A senior was applying to college and wondered how many applications she needed to send. Her counselor explained that with the excellent grade she received in chemistry she would probably be accepted to one school out of every three to which she applied. She immediately realized that for each application she would have to write 3 essays, and each essay would require 2 hours work. Of course writing essays is no simple matter. For each hour of serious essay writing, she would need to expend 500 calories which she could derive from her mother's apple pies. Every three times she cleaned her bedroom, her mother would make her an apple pie. How many times would she have to clean her room in order to gain acceptance to 10 colleges?

Units to a Power 3 How many m3 is 1500 cm3? 1 m 100 cm 1 m 100 cm 1 m

Units to a Power How many cm2 is 15 m2? 36 cm3 is how many mm3?

Three Systems for Measuring Temperature Section 1.7 Temperature Three Systems for Measuring Temperature Fahrenheit Celsius Kelvin Return to TOC Copyright © Cengage Learning. All rights reserved

The Three Major Temperature Scales Section 1.7 Temperature The Three Major Temperature Scales Return to TOC Copyright © Cengage Learning. All rights reserved

Converting Between Scales Section 1.7 Temperature Converting Between Scales Return to TOC Copyright © Cengage Learning. All rights reserved

React 4 At what temperature does °C = °F? Prove your answer. Copyright © Houghton Mifflin Company. All rights reserved. 1–28

0ºC is not 0ºF ºF 9 5 ºC

(0,32)= (C1,F1) ºF ºC

(0,32) = (C1,F1) (100,212) = (C2,F2) ºF ºC

At what temperature does °C = °F? Section 1.7 Temperature Exercise At what temperature does °C = °F? The answer is -40. Since °C equals °F, they both should be the same value (designated as variable x). Use one of the conversion equations such as °C = (°F- 32)(5/9), and substitute in the value of x for both °C and °F. Solve for x. Return to TOC Copyright © Cengage Learning. All rights reserved

Use one of the conversion equations such as: Section 1.7 Temperature Solution Since °C equals °F, they both should be the same value (designated as variable x). Use one of the conversion equations such as: Substitute in the value of x for both TC and TF. Solve for x. Return to TOC Copyright © Cengage Learning. All rights reserved

Temperature Solution Section 1.7 Return to TOC Copyright © Cengage Learning. All rights reserved

Mass of substance per unit volume of the substance. Section 1.8 Density Mass of substance per unit volume of the substance. Common units are g/cm3 or g/mL. Return to TOC Copyright © Cengage Learning. All rights reserved

Section 1.8 Density Example #1 A certain mineral has a mass of 17.8 g and a volume of 2.35 cm3. What is the density of this mineral? Return to TOC Copyright © Cengage Learning. All rights reserved

Section 1.8 Density Example #2 What is the mass of a 49.6-mL sample of a liquid, which has a density of 0.85 g/mL? Return to TOC Copyright © Cengage Learning. All rights reserved

Anything occupying space and having mass. Section 1.9 Classification of Matter Matter Anything occupying space and having mass. Matter exists in three states. Solid Liquid Gas Return to TOC Copyright © Cengage Learning. All rights reserved

The Three States of Water Section 1.9 Classification of Matter The Three States of Water Return to TOC Copyright © Cengage Learning. All rights reserved

Has fixed volume and shape. Section 1.9 Classification of Matter Solid Rigid Has fixed volume and shape. Return to TOC Copyright © Cengage Learning. All rights reserved

Classification of Matter Section 1.9 Classification of Matter Structure of a Solid Click below for visual concept while in play mode http://college.cengage.com/chemistry/zumdahl/chemistry/7e/assets/students/protected/fae/index.html?layer=act&src=qtiworkflowflash_1_11.xml&w=750&h=434 Return to TOC Copyright © Cengage Learning. All rights reserved

Has definite volume but no specific shape. Assumes shape of container. Section 1.9 Classification of Matter Liquid Has definite volume but no specific shape. Assumes shape of container. Return to TOC Copyright © Cengage Learning. All rights reserved

Classification of Matter Section 1.9 Classification of Matter Structure of a Liquid http://college.cengage.com/chemistry/zumdahl/chemistry/7e/assets/students/protected/fae/index.html?layer=act&src=qtiworkflowflash_1_15.xml&w=750&h=434 Text Return to TOC Copyright © Cengage Learning. All rights reserved

Has no fixed volume or shape. Section 1.9 Classification of Matter Gas Has no fixed volume or shape. Takes on the shape and volume of its container. Return to TOC Copyright © Cengage Learning. All rights reserved

Classification of Matter Section 1.9 Classification of Matter Structure of a Gas http://college.cengage.com/chemistry/zumdahl/chemistry/7e/assets/students/protected/fae/index.html?layer=act&src=qtiworkflowflash_1_14.xml&w=750&h=434 Return to TOC Copyright © Cengage Learning. All rights reserved

Have variable composition. Section 1.9 Classification of Matter Mixtures Have variable composition. Homogeneous Mixture Having visibly indistinguishable parts; solution. Heterogeneous Mixture Having visibly distinguishable parts. Return to TOC Copyright © Cengage Learning. All rights reserved

Classification of Matter Section 1.9 Classification of Matter Homogeneous Mixtures http://college.cengage.com/chemistry/zumdahl/chemistry/7e/assets/students/protected/fae/index.html?layer=act&src=qtiworkflowflash_1_13.xml&w=750&h=434 Return to TOC Copyright © Cengage Learning. All rights reserved

Homogeneous vs. Heterogeneous Mixtures Section 1.9 Classification of Matter Homogeneous vs. Heterogeneous Mixtures http://college.cengage.com/chemistry/zumdahl/chemistry/7e/assets/students/protected/fae/index.html?layer=act&src=qtiworkflowflash_1_10.xml&w=750&h=434 Return to TOC Copyright © Cengage Learning. All rights reserved

Classification of Matter Section 1.9 Classification of Matter Compound vs. Mixture http://college.cengage.com/chemistry/zumdahl/chemistry/7e/assets/students/protected/fae/index.html?layer=act&src=qtiworkflowflash_1_12.xml&w=750&h=434 Return to TOC Copyright © Cengage Learning. All rights reserved

Pure water Gasoline Jar of jelly beans Soil Copper metal Section 1.9 Classification of Matter Concept Check Which of the following is a homogeneous mixture? Pure water Gasoline Jar of jelly beans Soil Copper metal gasoline Return to TOC Copyright © Cengage Learning. All rights reserved

Key Terms: Properties A physical property is displayed by a sample of matter without undergoing any change in the composition of the matter. Physical properties include mass, color, volume, temperature, density, melting point, etc. Chemical property – displayed by a sample of matter as it undergoes a change in composition. Flammability, toxicity, reactivity, acidity are all chemical properties. Copper is red-brown, opaque, solid: physical properties. Ethanol is flammable: a chemical property. Prentice Hall © 2005 Chapter One General Chemistry 4th edition, Hill, Petrucci, McCreary, Perry

Change in the form of a substance, not in its chemical composition. Section 1.9 Classification of Matter Physical Change Change in the form of a substance, not in its chemical composition. Example: boiling or freezing water Can be used to separate a mixture into pure compounds, but it will not break compounds into elements. Distillation Filtration Chromatography Return to TOC Copyright © Cengage Learning. All rights reserved

Section 1.9 Classification of Matter Chemical Change A given substance becomes a new substance or substances with different properties and different composition. Example: Bunsen burner (methane reacts with oxygen to form carbon dioxide and water) Return to TOC Copyright © Cengage Learning. All rights reserved

Key Terms: Properties In a physical change, there is no change in composition. No new substances are formed. Examples include: evaporation; melting; cutting a piece of wood; dissolving sugar in water. In a chemical change or chemical reaction, the matter undergoes a change in composition. New substances are formed. Examples include: burning gasoline; dissolving metal in acid; spoilage of food. The vapor burns, combining with oxygen: a chemical change. The liquid fuel evaporates: a physical change. Prentice Hall © 2005 Chapter One General Chemistry 4th edition, Hill, Petrucci, McCreary, Perry

Pulverizing (crushing) rock salt Burning of wood Section 1.9 Classification of Matter Concept Check How many of the following are examples of a chemical change? Pulverizing (crushing) rock salt Burning of wood Dissolving of sugar in water Melting a popsicle on a warm summer day 1 (burning of wood) Return to TOC Copyright © Cengage Learning. All rights reserved

The Organization of Matter Section 1.9 Classification of Matter The Organization of Matter Return to TOC Copyright © Cengage Learning. All rights reserved

Classifying Matter Figure 1.9 Atoms Molecules make up ALL MATTER which exists as Substances Mixtures Pure which may be Elements Compounds Heterogeneous which may be Homogeneous Prentice Hall © 2005 Chapter One General Chemistry 4th edition, Hill, Petrucci, McCreary, Perry

The Organization of Matter Mixtures: a) Homogeneous (Solutions) b) Heterogeneous Pure Substances Elements Compounds Atoms Nucleus Electrons Protons Neutrons Quarks Quarks

General Chemistry 4th edition, Hill, Petrucci, McCreary, Perry Classifying Matter A (pure) substance has a definite or fixed composition that does not vary from one sample to another. All substances are either elements or compounds. An element cannot be broken down into other simpler substances by chemical reactions. About 100 elements known at this time Each element has a chemical symbol: O, H, Ag, Fe, Cl, S, Hg, Au, U, etc. A compound is made up of two or more elements in fixed proportions, and can be broken down into simpler substances. Carbon dioxide, sodium chloride, sucrose (sugar), etc. Prentice Hall © 2005 Chapter One General Chemistry 4th edition, Hill, Petrucci, McCreary, Perry

General Chemistry 4th edition, Hill, Petrucci, McCreary, Perry Classifying Matter A mixture does not have a fixed composition. A homogeneous mixture has the same composition throughout, though the composition of different homogeneous mixtures may vary. Soda pop, salt water, 14K gold, and many plastics are homogeneous mixtures. 10K gold and 14K gold have different compositions but both are homogeneous. A heterogeneous mixture varies in composition and/or properties from one part of the mixture to another. Adhesive tape, CD, pen, battery, chair, and people are examples of heterogeneous mixtures. Most everyday “stuff” consists of mixtures. Prentice Hall © 2005 Chapter One General Chemistry 4th edition, Hill, Petrucci, McCreary, Perry

The Organization of Matter Copyright © Houghton Mifflin Company. All rights reserved. 1–39

Phase Differences Solid – definite volume and shape; particles packed in fixed positions. Liquid – definite volume but indefinite shape; particles close together but not in fixed positions Gas – neither definite volume nor definite shape; particles are at great distances from one another Plasma – high temperature, ionized phase of matter as found on the sun.

Properties of Matter Extensive properties depend on the amount of matter that is present. Volume Mass Energy Content (think Calories!) Intensive properties do not depend on the amount of matter present. Melting point Boiling point Density

Separation of a Mixture The constituents of the mixture retain their identity and may be separated by physical means.

Separation of a Mixture The components of dyes such as ink may be separated by paper chromatography.

Figure 1.15a A Line of the Mixture to be Separated is Placed at One End of a Sheet Copyright © Houghton Mifflin Company. All rights reserved. 1–

Figure 1.15b The Paper Acts as a Wick to Draw up the Liquid Copyright © Houghton Mifflin Company. All rights reserved. 1–

Figure 1.15c Component with the Weakest Attraction for the Paper Travels Faster Copyright © Houghton Mifflin Company. All rights reserved. 1–

Separation of a Mixture by Distillation

Separation of a Compound The Electrolysis of water Compounds must be separated by chemical means. With the application of electricity, water can be separated into its elements Reactant Products Water  Hydrogen + Oxygen 2 H2O 2 H2 + O2

React 5 Sketch a magnified view (showing atoms/molecules) of each of the following: a heterogeneous mixture of two different compounds. a homogeneous mixture of an element and a compound. Copyright © Houghton Mifflin Company. All rights reserved. 1–43