unit 4 Flashcards
matter
occupies space and contains mass
homogenous mixture
visibly indistinguishable parts (batter)
heterogenous mixture
visibly distinguishable parts
pure substance
substance with one constant composition
compound
substance with constant composition that can be broken down into elements by chemical process.
- water
- table salt
elements
substance that cannot be decomposed into simpler substances by physical or chemical means
- oxygen
- hydrogen
physical change
substance changes without changing the composition
-usually reversible
chemical change
substance changed- breaking or creation of bonds
-produce new substances with new properties
evidence of chemical change
- production of precipitate
- color change
- change in energy (light, temp, sound)
- gas production (bubbles/cloudiness)
reaction types
-synthesis
-decomposition
- combustion
- single replacement
- double replacement
synthesis reaction
2 or more substance combine into single substance
decomposition reaction
1 compound splits into 2 simple substances
single replacement
one element replaces a similar element in a compound.
double replacement
positive and negative ions of two ionic compound exchange places to form two new compounds
combustion
burning; chem reaction, substance reacts quickly with O2 releasing energy in form of light and heat.
law of conservation of mass
matter cannot be created or destroyed, only transformed
diatomic
consist of 2 atoms
-O2
-F2
-H2
-Br2
- I2
- N2
- Cl2
net ionic equations
only show particles that change in the reaction cancelling out the spectator ions
stoichiometry
conversions that involve mole ratios from a balanced chemical equation
percent yield
actual yield/theoretical yield *100
acid base titration
changes color when close to 7 pH
redox titrations
color change produced when oxidation state of a metal ion in the reaction changes.
precipitation titration
titrant reacts with ions in analyte, precipitation can occur. formation of precipitation or color change can signal end point
