1 1-1 © 2004 Thomson Learning, Inc. All rights reserved General, Organic, and Biochemistry, 7e Bettelheim, Brown, and March

1 1-2 © 2004 Thomson Learning, Inc. All rights reserved Chapter 1 Matter, Energy, and Measurement Matter, Energy, and Measurement

1 1-3 © 2004 Thomson Learning, Inc. All rights reserved Chemistry Chemistry is the study of matter matter is anything that has mass and takes up space Matter can change from one form to another in a chemical reaction (chemical change), substances are used up and others formed in their place Example: Example: when propane (bottled gas) burns in air, propane and oxygen are converted to carbon dioxide and water in a physical change, matter does not lose its identity Example: Example: ice (solid water) melts to become liquid water; liquid water boils to become steam (gaseous water)

1 1-4 © 2004 Thomson Learning, Inc. All rights reserved Scientific Method

1 1-5 © 2004 Thomson Learning, Inc. All rights reserved Exponential Notation Used to represent very large or very small numbers as powers of 10 Examples: is written as 2 x ,000,000 is written as 2 x 10 6

1 1-6 © 2004 Thomson Learning, Inc. All rights reserved Metric System Base units in the metric system

1 1-7 © 2004 Thomson Learning, Inc. All rights reserved Metric System The most common metric prefixes

1 1-8 © 2004 Thomson Learning, Inc. All rights reserved Metric & English Systems Some conversion factors

1 1-9 © 2004 Thomson Learning, Inc. All rights reserved Mass and Weight Mass: Mass: the quantity of matter in an object mass is independent of location Weight: Weight: the result of mass acted upon by gravity weight depends on location; depends on the force of gravity at the particular location

© 2004 Thomson Learning, Inc. All rights reserved Temperature Fahrenheit (F): Fahrenheit (F): defined be setting freezing point of water at 32°F and the boiling point of water at 212°F Celsius (C): Celsius (C): defined by setting freezing point of water at 0°C and boiling point of water at 100°C Kelvin (K): Kelvin (K): zero is the lowest possible temperature; also called the absolute scale degree is the same size as Celsius degree K = °C + 273

© 2004 Thomson Learning, Inc. All rights reserved Factor-Label Method Conversion factor Conversion factor a ratio, including units, used as a multiplier to change from one system or unit to another for example, 1 lb = g Example:Example: convert 381 grams to pounds Example:Example: convert gallons to milliliters

© 2004 Thomson Learning, Inc. All rights reserved The Three States of Matter Gas Gas has no definite shape or volume fills whatever container it is put into is highly compressible Liquid Liquid has no definite shape but a definite volume is slightly compressible Solid Solid has a definite shape and volume is essentially incompressible

© 2004 Thomson Learning, Inc. All rights reserved Density Density: Density: the ratio of mass to volume most commonly used units are g/mL for liquids and solids, and g/L for gases. Example:Example: If 73.2 mL of a liquid has a mass of 61.5 g, what is its density in g/mL?

© 2004 Thomson Learning, Inc. All rights reserved Specific Gravity Specific gravity: Specific gravity: the density of a substance compared to water as a standard because specific gravity is the ratio of two densities, it has no units (it is dimensionless) Example:Example: the density of copper at 20°C is 8.92 g/mL. The density of water at this temperature is 1.00 g/mL. What is the specific gravity of copper?

© 2004 Thomson Learning, Inc. All rights reserved Energy Energy: Energy: the capacity to do work may be either kinetic energy of potential energy the calorie (cal) is the base metric unit Kinetic energy: Kinetic energy: the energy of motion KE increases as the object’s velocity increases at the same velocity, a heavier object has greater KE Potential energy: Potential energy: the energy an object has because of its position; stored energy

© 2004 Thomson Learning, Inc. All rights reserved Energy Examples of kinetic energy are mechanical energy, light, heat, and electrical energy In chemistry, the most important form of potential energy is chemical energy chemical energy is stored in chemical substances, as for example in foods such as carbohydrates and fats it is given off when substances take part in chemical reactions The law of conservation of energy energy can neither be created nor destroyed energy can only be converted from one form to another

© 2004 Thomson Learning, Inc. All rights reserved Heat and Temperature Heat is a form of energy heating refers to the energy transfer process when two objects of different temperature are brought into contact heat energy always flows from the hotter object to the cooler one until the two have the same temperature heat is commonly measured in calories (cal), which is the heat necessary to raise the temperature of 1 g of liquid water by 1°C

© 2004 Thomson Learning, Inc. All rights reserved Specific Heat Specific heat: Specific heat: the amount of heat necessary to raise the temperature of 1 g of a substance by 1°C.

© 2004 Thomson Learning, Inc. All rights reserved Specific Heat The following equation gives the relationship between specific heat, amount of heat, the mass of an object, and the change in temperature Example:Example: how many calories are required to heat 352 g of water from 23°C to 95°C?

© 2004 Thomson Learning, Inc. All rights reserved End Chapter 1 Matter, Energy, and Measurement