Chemistry Mid-Term
Terms
undefined, object
copy deck
- Steps in the scientific method
-
1)form an observation
2)formulate a hypothesis
3)experiment
4)form a conclusion - defintion of law
- rule of nature that sums up related observations and experimental results to DESCRIBE a pattern in nature
- theory
- EXPLANATION based on many observations supported by experimental data; can never be proven, used as a working format
- shows kinds and numbers of atoms in the smallest representative unit
- chemical formula
- how to write chemical formulas
- Symbol (C, H, O) and then Subscript
- result of a chemical change
- chemical reaction
- how to write chemical reactions
- Reactants--->Products
- physical property
- observed property that can be altered without changing its chemical composition
- chemical property
- characteristic of a material that controls a material's action with other materials
- ex. of physical properties
- melting, freezing, dissolving, breaking
- ex. of chemical properties
- rusting, burning
- molar mass
- mass of a mole of any substance
- kilo=
- 1000
- deci=
- 1/10
- centi=
- 1/100
- milli=
- 1/1000
- how to convert Kelvins to Celsius
- C=K-273 and K=C+273
- dimensional analysis
- uses of units that are part of measurements to solve a problem
- subatomic particles--what charge and where located
-
electrons: negatively-charged, located in energy levels outside the nucleus
protons: positively-charged, located within the nucleus
neutrons: neutral charge, located within the nucleus - atomic mass
- 1/12 the mass of a Carbon 12 atom that contains 6 protons and 6 neutrons
- atomic number
- number or protons in the nucleus of an atom
- isotopes
- atoms with the same number of protons but different number of neutrons
- formula unit
- lowest whole number ratio of ions in an ionic compound
- polyatomic ion
- tightly-bound groups of atoms that behave as a unit and carry a charge
- polyatomic ions end in...
- -ate or -ite
- compound composed of 2 elements --metal cation plus nonmetal anion
- ionic binary compound
- ionic binary compound naming
- 1)name of cation first 2)anion ends in -ide
- compounds composed of 2 non-metallic elements
- molecular binary compound
- molecular binary compound naming
- use prefixes to indicate number of atoms of each element, second element ends in -ide
- S+O2--->SO2
- combination
- SO2--->S+O2
- decomposition
- Fe+CuSO4--->FeSO4+Cu
- single-replacement
- AgNO3+KCl--->AgCl+KNO3
- double-replacement
- CH4+2HO2--->CO2+2H2O+heat+light
- combustion
- acid
- compounds that release hydrogen ions when dissolved in water
- endothermic
- absorbs heat from surroundings--positive
- exothermic
- releases heat to its surroundings-negative
- STP for gases
- 0 degrees C and pressure of 101.3kPa or 1 atm
- specific heat formula
-
Heat (joules or calories)
-------------------------
mass x change in temp C
q
-----
m x T