Chapter 3 Flashcards
A prediction or statement that can be tested is a(n)
hypothesis
Which of the following is a quantitative piece of information?
1) Smells like bananas
2) reddish color
3) 44 degrees C
4) gigantic
3) 44 degrees celsius
Quantitative data is any numerical information describing how much, how little, how big, how tall, how fast, etc. Or in this case, how hot!
Qualitative data is any information describing color, odor, shape, or some other physical characteristic.
What is the law of conservation of mass?
This law states that mass is neither created nor destroyed during a chemical reaction- it is conserved.
Which state of matter has a constant volume, takes the shape of its container, has particles which move past each other, and cannot be compressed?
Liquid
Which state of matter has a definite shape, volume, tightly packed particles, and cannot be compressed?
Solid
Which state of matter has a volume that is not constant, takes the shape of its container, has particles which move freely to fill a container, and can be compressed?
Gas
What is a physical property?
A characteristic that can be observed/measured without changing the sample’s composition (ie density, color, odor, taste, etc)
What is the first type of physical property?
Extensive-
A type of physical property that depends on the amount of substance present (ie mass, length, volume, etc)
What is the second type of physical property?
Intensive-
A type of physical property that’s independent of the amount of substance present (ie density, color, temperature)
What is a chemical property?
The ability of a substance to combine with or change into another substance (ie chemical reaction such as an iron nail having the ability to rust)
What is an experiment?
A set of controlled observations that test a hypothesis
In an experiment, what is the independent variable?
The variable that you plan on changing (you control this variable)
In an experiment, what is the dependent variable?
The variable that changes because of the independent variable (you don’t control this variable)
In an experiment, what is the control?
The control is something in an experiment that is kept unchanged with the purpose of comparison
Filtration
A technique that uses a porous (having small holes) barrier to separate a solid from a liquid.
(ie a mixture is poured through a filter paper folded into a cone shape, leaving solids trapped in the filter)
Distillation
A technique in which homogeneous mixtures (a mixture with the same amount of components throughout) can be separated by boiling it to separate them
(ie a mixture is heated till substance with the lowest boiling point boils to a vapor, which can then be condensed and collected.
Crystallization
A separation technique that results in formation of pure solid particles of a substance from a solution containing the dissolved substance. It produces HIGHLY pure solids.
(ie rock candy; water evaporates from sugar and leaves the sugar left as a crystallized substance on a string)
Chromatography
A technique which separates components of a mixture on basis of the tendency of each to travel/be drawn across the surface of another material.
(ie various components of ink spreads through a paper at different rates, separating the ink)
Mixture
A combination of 2 or more substances in which each pure substance retains its individual chemical properties
Heterogeneous Mixture
One that does not blend smoothly throughout and in which the individual substances remain distinct
Homogeneous Mixture
One that has a constant composition throughout; it always has a single phase.
Element
A pure substance that cannot be separated into simpler substances by physical or chemical means.
Compound
a combination of two or more different substances and mixtures
Law of Definite Proportions
Regardless of the amount, a compound is always composed of the same elements in the same proportion by mass.
Law of Multiple Proportions
When different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other element in a ratio of small whole numbers.
