Introduction to Chemistry Chapter 1 Dr. Yager
Matter and Chemistry Matter is anything that has mass and occupies space. Chemistry is the study of the composition of matter and the changes that matter undergoes.
Five Traditional Areas of Chemistry Organic chemistry Inorganic chemistry Biochemistry Analytical chemistry Physical chemistry
Organic chemistry is defined as the study of all chemicals containing carbon.
Inorganic chemistry is the study of chemicals that, in general, do not contain carbon. Adult bone is 5% living cells, 95% non-living material. About 30% of bone by dry weight is organic, while the rest is inorganic (minerals).
The study of processes that take place in organisms is biochemistry.
Analytical chemistry is the study of the composition of matter.
Physical chemistry deals with the mechanism, the rate, and the energy transfer that occurs when matter undergoes a change.
Pure and Applied Chemistry Pure chemistry is the pursuit of chemical knowledge for its own sake. Applied chemistry is research that is directed toward a practical goal or application.
Chemists Design Materials In 1948, George de Mestral took a close look at the burrs that stuck to his clothing. He saw that each burr was covered with many tiny hooks. In 1955, de Mestral patented the design for the hook-and- loop tapes. These are used as fasteners in shoes and gloves.
SEAgel is a modern insulation that is light enough to float on soap bubbles. One of the easiest ways to conserve energy is through insulation. Insulation acts as a barrier to heat flow from the inside to the outside of a house or from the outside to the inside of a freezer.
Chemists also help determine when a crop needs water. If the genes from a jellyfish that glows are transferred to a potato plant, the plant glows when it needs to be watered.
Chemists sometimes use chemicals produced by insects to fight insect pests. The plastic tube wrapped around the stem of the tomato plant contains a chemical that a female pinworm moth emits to attract male moths. It interferes with the mating process so that fewer pinworms are produced.
Until the mid-1900s, lead was used in many products, including paints and gasoline. In 1971, a study showed that the level of lead that is harmful to humans is much lower than previously thought, especially for children. Even low levels of lead in the blood can permanently damage the nervous system of a growing child. In 1971, a study showed that the level of lead that is harmful to humans is much lower than previously thought, especially for children. Even low levels of lead in the blood can permanently damage the nervous system of a growing child.
Chemists have analyzed more than 850 pounds of moon rocks that were brought back to Earth. Some of these rocks are similar to rocks formed by volcanoes on Earth, suggesting that vast oceans of molten lava once covered the moon's surface. fini
Before Chemists There Were Alchemists Alchemists wanted to turn lead to gold. They wanted to do other magic tricks like create life.
Alchemists developed processes for separating mixtures and purifying chemicals. They designed equipment that is still in use today including beakers, flasks, tongs, funnels, and the mortar and pestle. Alchemists developed processes for separating mixtures and purifying chemicals. They designed equipment that is still in use today including beakers, flasks, tongs, funnels, and the mortar and pestle. Alchemists’ Contribution
Antoine-Laurent Lavoisier Father of modern chemistry Transformed chemistry from a science of observation to the science of measurement ( gm scale) Showed that oxygen is required for a material to burn using the scientific method Beheaded during the French Revolution
Scientific Method A logical, systematic approach to the solution of a scientific problem Steps Include: making observations making observations doing experiments doing experiments testing hypotheses testing hypotheses developing theories developing theories
An experiment is a procedure that is used to test a hypothesis. When you design experiments, you deal with variables, or factors that can change. An experiment is a procedure that is used to test a hypothesis. When you design experiments, you deal with variables, or factors that can change. The variable that you change during an experiment is the manipulated variable, or independent variable. The variable that you change during an experiment is the manipulated variable, or independent variable. The variable that is observed during the experiment is the responding variable, or dependent variable. The variable that is observed during the experiment is the responding variable, or dependent variable.
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Theory Once a hypothesis meets the test of repeated experimentation, it may become a theory. A theory is a well-tested explanation for a broad set of observations. A theory may need to be changed at some point in the future to explain new observations or experimental results.
Scientific Law A scientific law is a concise statement that summarizes the results of many observations and experiments. A scientific law doesn’t try to explain the relationship it describes. That explanation requires a theory.
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“Real” Science Run another test to get results “journal ready” Notice something interesting and unexpected Can’t Get Good Readings Power Goes out for an Hour Machine Breaks Go to conference, get distracted by new idea Realize you don’t have tools to analyze results Teaching undergrads, no time to find answers
Problem Solving in Chemistry
Analyze To solve a word problem, you must first determine where you are starting from (identify what is known) and where you are going (identify the unknown). After you identify the known and the unknown, you need to make a plan for getting from the known to the unknown.
Calculate If you make an effective plan, doing the calculations is usually the easiest part of the process.
Evaluate Check that your answer is reasonable and makes sense. Check that it has the correct units and the correct number of significant figures.
Practice Problem
Conceptual Problems
Homework?
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