Principles of General Chemistry Review

Practice flashcards for Chapter 1 and 2, covering matter, energy, SI units, uncertainty, and atomic theory overview.

How is chemistry defined in the lecture notes?

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

What is the difference between a physical change and a chemical change?

A physical change occurs when a substance alters its physical properties but not its composition, while a chemical change (or chemical reaction) occurs when a substance is converted into a different substance.

How are the three states of matter defined macroscopically?

A solid has a fixed shape, a liquid has a varying shape with an upper surface that conforms to the container, and a gas fills the entire container and has no surface.

What is the difference between potential energy and kinetic energy?

Potential energy is the energy due to the position of the object relative to other objects, whereas kinetic energy is the energy due to the motion of the object.

State the two central concepts regarding energy conversion mentioned in the notes.

1. When energy is converted from one form to another, it is conserved, not destroyed. 2. Situations of lower energy are more stable and favored over situations of higher energy.

What are the components of the scientific approach?

Observations (quantitative data or natural laws), Hypothesis (testable proposal), Experiment (controlled test of variables), and Model (theory that explains data).

What is a conversion factor?

A ratio of equivalent quantities used to express a single quantity in different units.

What is the SI base unit for mass, and why is it unique?

The kilogram ($kg$); it is the only base unit whose standard is an object and whose name includes a prefix.

What is the formula for density?

$$\text{Density} = \frac{\text{mass}}{\text{volume}}$$

How do you convert Celsius to Kelvin?

$$T (\text{in K}) = T (\text{in } ^\circ\text{C}) + 273.15$$

How do you convert Celsius to Fahrenheit?

$$T (\text{in } ^\circ\text{F}) = \frac{9}{5}T (\text{in } ^\circ\text{C}) + 32$$

Distinguish between extensive and intensive properties.

Extensive properties (e.g., mass, volume) depend on the amount of substance present; intensive properties (e.g., density, temperature) do not.

What is the rule for significant figures in addition and subtraction?

The answer has the same number of decimal places as the measurement with the fewest decimal places.

What is the rule for significant figures in multiplication and division?

The answer contains the same number of significant figures as the measurement with the fewest significant figures.

Distinguish between precision and accuracy.

Precision refers to how close measurements in a series are to each other (reproducibility); accuracy refers to how close a measurement is to the actual value.

What is the difference between systematic error and random error?

Systematic error produces values that are either all higher or all lower than the actual value, while random error produces values both higher and lower than the actual value.

What is the simplest type of matter with unique properties?

An element, which consists of only one kind of atom and cannot be broken down by physical or chemical methods.

What is a compound?

A substance composed of two or more different elements that are chemically combined in a fixed ratio.

How does a mixture differ from a substance?

A mixture consists of two or more substances that are physically intermingled and has a variable composition, whereas a substance has a fixed composition.

Who was the father of atomism mentioned in the notes?

Democritus, who reasoned that matter is composed of indivisible particles called atoms (atomos).