Final Exam Flashcards
Why is the scope of chemistry so vast?
Everything is made of matter!
5 areas of chemistry
Analytical chemistry Organic chemistry Inorganic chemistry Physical chemistry Biochemistry
Matter
Anything that has mass and occupies space
Organic chemistry
Study of compounds containing carbon
Inorganic chemistry
Study of substances that do not contain carbon
Biochemistry
Studies processes that take place in organisms
Analytical chemistry
Focuses on the composition of matter
Physical chemistry
Deals w/mechanism, rate, and energy transfer when matter undergoes a change
Pure chemistry
Pursuit of chemical knowledge for its own sake
Applied chemistry
Research directed toward a practical goal/application
3 reasons to study chemistry
Explain the natural world, prepare for career opportunities, produce informed citizens
4 outcomes of modern chemistry research
Leads to technologies that:
- Benefit the environment
- Conserve and produce energy
- Improve human life
- Expand knowledge of the universe
Technology
The means by which a society provides its members with things needed and desired
How did Lavoisier transform chemistry?
He transformed it from a science of observation into a science of measurement
Steps in scientific method
- Make an observation
- Form a hypothesis
- Test the hypothesis
- Develop a theory
What role do collaboration and communication play in science?
Increase the likelihood of a successful outcome
Mass
Measure of the amount of matter an object contains
Volume
Measure of the space occupied by an object
Extensive property
Property that depends on the amount of matter in a sample
Intensive property
Property that depends on the type of matter in a sample
Substance
Matter that has a uniform and definite composition
Physical property
Can be observed/measured without changing the substance’s composition
Solid
Form of matter that has a definite shape and volume
Liquid
Form of matter that flows, has a fixed volume, and an indefinite shape
Gas
Form of matter that takes the shape and volume of its container; no definite shape or volume
Vapor
Gaseous state of a substance that is generally a liquid or solid at room temperature (ex. “water vapor”)
Physical change
Change during which some physical properties of a material change, but its composition doesn’t change
Why do all samples of a substance have the same intensive properties?
They all have the same composition
How can physical changes be classified?
As reversible or irreversible
Mixture
Physical blend of two or more substances that aren’t chemically combined
How can mixtures be classified?
As heterogenous or homogenous
Heterogenous mixture
Mixture in which the composition is not uniform throughout
Homogenous mixture
Mixture that has a uniform composition
Aka a solution
Phase
Any part of a sample with uniform composition and properties
Filtration
Process that separates a solid from a liquid in heterogenous mixture
Distillation
Process used to separate components of a mixture using differences in boiling points
Element
The simplest form of matter that has a unique set of properties
Compound
Substance that contains two or more elements chemically combined in fixed proportion
How do compounds differ from elements?
Compounds can be broken down into simpler substances; elements cannot
Chemical change
Change that produces matter with a different composition than the original matter
How can substances and mixtures be distinguished?
If the composition is fixed, it’s a substance. If the composition may vary, it’s a mixture
Chemical symbol
One-or two-letter representation of an element
Period
Horizontal row of elements in the periodic table
Group
A vertical column of elements in the periodic table
Measurement
Quantity that has a number and unit
Multiplying numbers in sci notation
Multiply coefficients, add exponents
Dividing numbers in sci notation
Divide coefficients, subtract the exponent in the denominator from the exponent in the numerator
Adding and subtracting numbers in sci notation
First, align the exponents by moving the decimal points, then add or subtract the coefficients
Accuracy
Closeness of a measurement to the true value of what is being measured
Precision
The closeness or reproducibility of a set of measurements take under same conditions
Accepted value
A quantity used by general agreement of the scientific community
Experimental value
Quantitative value measured during an experiment
Error
Experimental value - accepted value
Percent error
absolute value of error/accepted value x 100%
Significant figures
All the digits that can be known precisely in a measurement, plus a last estimated digit
Adding/subtracting with sig figs
Answer should be rounded to the same number of decimal places as the measurement with the least number of decimal places
Multiplying/dividing with sig figs
Answer should be rounded to the same number of sig figs as the measurement with the least number of sig figs
