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Chem 211 Chapter 1
Chapter 1
42
Chemistry
Undergraduate 4
09/04/2017

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Term

  

What is Chemistry?

Definition

The scientific study of matter and its properties, the changes that matter undergoes, and the energy associated with those changes

Term

 

 

What is Matter?

Definition

 

is the “stuff ” of the universe: air, glass, planets, students—anything that has mass and volume.

Term

 

What is the composition of matter?

Definition

 

the types and amounts of simpler substances that make it up

Term

 

What is a substance?

Definition

 

 

is a type of matter that has a defined, fixed composition.

Term
What three physical states does matter commonly occur in?
Definition

 

solid, liquid, and gas

Term

 

Define a solid

Definition
has a fixed shape that does not conform to the container shape. Solids are not defined by rigidity or hardness: solid iron is rigid and hard, but solid lead is flexible, and solid wax is soft.
Term

 

Define a liquid

Definition
Term

 

Define a gas

Definition

 

Has a varying shape that conforms to the container shape, but it fills the entire container and, thus, does not have a surface.

Term

 

 

Solid

Definition
[image]
Term

 

 

Liquid

Definition
[image]
Term

 

 

Gas

Definition
[image]
Term

 

Define: Properties

Definition

 

The characteristics that give each substance its unique identity.

Term

 

What are the two types of changes that matter undergoes?

Definition

Physical Change (No Change in Composition)

Chemical Change (A Change in Composition)

 

Term

 

How do you identify a substance?

Definition

 

By observing two types of properties: Physical and Chemical

Term

 

 

Define: Physical Properties

Definition

 

Characteristics a substance shows by itself, without changing into or interacting with another substance. 

(These properties include color, melting point, electrical conductivity, and density.)

Term

 

 

Define: Physical Change

Definition

 

Occurs when a substance alters its physical properties, not its composition.

(For example, when ice melts, several physical properties change, such as hardness, density, and ability to flow.)

Term

 

Define: Chemical change

(also known as Chemical Reaction)

Definition

 

Occurs when one or more substances are converted into one or more substances with different composition and properties.

(Water-----(electrical current)----->hydrogen + oxygen)

Term

 

 

Define: Chemical properties

Definition

 

Characteristics a substance shows as it changes into or interacts with another substance (or substances).

 

(Chemical properties include flammability, corrosiveness, and reactivity with acids.)

Term

 

What is energy?

Definition

 

The ability to do work.

(Physical and chemical changes are accompanied by energy changes)

Term

 

Define total energy

Definition

 

The sum of its potential energy and its kinetic energy.

Term

 

What is Potential Energy?

Definition

 

 The energy due to the position of the object relative to other objects.

Term

 

 

What is Kinetic Energy?

Definition

 

 The energy due to the motion of the object.

Term

 

What are the two central concepts of energy in the study of matter?

Definition

 

  1. When energy is converted from one form to the other, it is conserved, not destroyed.

  2. Situations of lower energy are more stable and are favored over situations of higher energy, which are less stable.

Term

"The four cases"

1. A weight raised above the ground

2. Two balls attached by a spring 

3. Two electrically charged particles

4. A fuel and its waste products
[image]

Definition

The energy you exert to lift a weight against gravity increases the weight’s potential energy (energy due to its position). When you drop the weight, that additional potential energy is converted to kinetic energy (energy due to motion). The situation with the weight elevated and higher in potential energy is less stable, so the weight will fall when released, resulting in a situation that is lower in potential energy and more stable.

Term

"The four cases"

1. A weight raised above the ground

2. Two balls attached by a spring 

3. Two electrically charged particles

4. A fuel and its waste products

[image]

Definition

When you pull the balls apart, the energy you exert to stretch the relaxed spring increases the system’s potential energy. This change in potential energy is converted to kinetic energy when you release the balls. The system of balls and spring is less stable (has more potential energy) when the spring is stretched than when it is relaxed.

Term

"The four cases"

1. A weight raised above the ground

2. Two balls attached by a spring 

3. Two electrically charged particles

4. A fuel and its waste products

[image]

Definition

Due to interactions known as electrostatic forces, opposite charges attract each other, and like charges repel each other. When energy is exerted to move a positive particle away from a negative one, the potential energy of the system increases, and that increase is converted to kinetic energy when the particles are pulled together by the electrostatic attraction. Similarly, when energy is used to move two positive (or two negative) particles together, their potential energy increases and changes to kinetic energy when they are pushed apart by the electrostatic repulsion. Charged particles move naturally to a more stable situation (lower energy).

Term

"The four cases"

1. A weight raised above the ground

2. Two balls attached by a spring 

3. Two electrically charged particles

4. A fuel and its waste products

[image]

Definition

Matter is composed of positively and negatively charged particles. The chemical potential energy of a substance results from the relative positions of its particles and the attractions and repulsions among them. Some substances are higher in potential energy than others. For example, gasoline and oxygen have more chemical potential energy than the exhaust gases they form. This difference is converted into kinetic energy, which moves the car, heats the interior, makes the lights shine, and so on. Similarly, the difference in potential energy between the food and air we take in and the wastes we excrete enables us to move, grow, keep warm, study chemistry, and so on.

Term

 

What is the alchemical tradition?

Definition
Alchemy was an occult study of nature that began in the 1st century AD and dominated thinking for over 1500 years. Originally influenced by the Greek idea that matter strives for “perfection,” alchemists later became obsessed with converting “baser” metals, such as lead, into “purer” ones, such as gold. They invented distillation, percolation, and extraction and devised apparatus still used routinely today (Figure 1.4). But perhaps even more important was that alchemists encouraged observation and experimentation, which replaced the Greek approach of explaining nature solely through reason.
Term

 

What is the medical tradition?

Definition
Alchemists also influenced medical practice in medieval Europe. And ever since the 13th century, distillates and extracts of roots, herbs, and other plant matter have been used as sources of medicines. The alchemist and physician Paracelsus (1493–1541) considered the body to be a chemical system and illness an imbalance that could be restored by treatment with drugs. Thus began the alliance between medicine and chemistry that thrives today.
Term

 

What is the technological tradition?

Definition
Pottery making, dyeing, and especially metallurgy contributed greatly to people’s experience with materials. During the Middle Ages and the Renaissance, books were published that described how to purify, assay, and coin silver and gold, how to use balances, furnaces, and crucibles, and how to make glass and gunpowder. Some of the books introduced quantitative measurement, which was lacking in alchemical writings. Nevertheless, the skilled artisans showed little interest in why a substance changes or how to predict its behavior.
Term

 

What is Combustion?

Definition

 

The process of burning a material in air, often with the release of heat and light. 

Term

 

What is the phlogiston theory?

Definition

 

It proposed that combustible materials contain phlogiston, an undetectable substance released when the material burns.

Term

 

Who is Antoine Lavoisier (1743–1794)?

Definition

He was a French chemist that resolved the conflict over phlogiston, through experimentation: 

  1. Heating mercury calx decomposed it into two products—mercury and a gas—whose total mass equaled the starting mass of the calx.

  2. Heating mercury with the gas reformed the calx, and, again, the total mass remained constant.

  3. Heating mercury in a measured volume of air yielded mercury calx and left four-fifths of the air remaining.

 

A burning candle placed in the remaining air was extinguished.

Lavoisier named the gas oxygen and gave metal calxes the name metal oxides. His explanation of his results made the phlogiston theory irrelevant:

 

  • Oxygen, a normal component of air, combines with a substance when it burns.

  • In a closed container, a combustible substance stops burning when it has combined with all the available oxygen.

  • A metal calx (metal oxide) weighs more than the metal because its mass includes the mass of the oxygen.

This new theory triumphed because it relied on quantitative, reproducible measurements, not on strange properties of undetectable substances. Because this approach is at the heart of science, many propose that the science of chemistry began with Lavoisier.

Term
What is the scientific method?
Definition
To understand nature, scientists use this approach. A process of creative proposals and testing aimed at objective, verifiable discoveries of the causes of natural events. It includes observations, hypothesis, experiment, model (theory), and further experimentation.
Term
Define Observations
Definition
A fact obtained with the senses, often with the aid of instruments. Quantitative observations provide data that can be compared.
Term
What is Data?
Definition
Pieces of quantitative information obtained by observation.
Term
Define Natural law
Definition
A summary, often in mathematical form, of a universal observation. When the same observation is made by many investigators in many situations with no clear exceptions
Term
Define Hypothesis
Definition
A testable proposal made to explain an observation. If inconsistent with experimental results, a hypothesis is revised or discarded.
Term
Define Experiment.
Definition
A set of procedural steps that tests a hypoth­esis.
Term
Define variable.
Definition
A quantity that can have more than a single value
Term
Define controlled experiment
Definition
An experiment that measures the effect of one variable at a time by keeping other variables constant.
Term
Define model
Definition
A simplified conceptual picture based on experiment that explains how a natural phenomenon occurs.
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