Unit 1 Flashcards
What are the rules for significant digits?
- all non-zero digits are significant
- all final zeros after the decimal point are significant
- zeros between two other significant digits are significant
- zeros used only for spacing the decimal point are not significant
Multiplication and Division of SF
The answer has the same number of SF as the least number of SF in the question
Addition and Subtraction
The answer must have the same precision as the least precise value in the question.
Isotope
an atom of an element with a different number of neutrons than the original element
Atomic Mass
The weighted average of the different isotopes of an atom
Inorganic Chemistry
chemistry with molecules not based on a carbon chain
Ion
An atom that does not have equal numbers of protons and electrons
Ionic Compound
A neutral species that forms between a metal ion and a non-metal ion
Covalent Compound
A neutral species with atoms bonded together by sharing electrons.
Monatomic Ion
A single atom acting as an ion.
Binary ionic compounds are compounds of two monatomic ions.
Polyatomic Ion
Several atoms covalently bonded together acting as one ion.
What’s a mole?
6.02 x 10 ^ 23 atoms
Molar mass is the mass of one mole of a substance, with units in g mol-1.
What’s formula mass?
Formula mass is substituted for molar mass in ionic compounds since they don’t form discrete molecules.
How do you find percent composition?
mass of one element in a compound / mass of total compound x 100%
Empirical Formula
the simplest ratio of the elements in a compound
Ionic compounds only have an empirical formula since they’re already in lowerst terms
Molecular Formula
The actual number of elements present in a covalent compound.
How do you find the formula from the percent composition?
Convert all mass percents to moles, then find the ratio of moles
How do you find the molecular formula?
The molar mass of the compound must be compared to the molar mass of the empirical formula.
Balancing Tips
- Diatomic: H2, N2, O2, F2, Cl2, Br2, I2
2. Balance elements last
What is stoichiometry?
Stoichiometry is the branch of chemistry that deals with calculating the amounts of reactants and products involved in a chemical reaction.
Steps for a stoichiometric calculation?
- Determine the balanced reaction
- Convert the amount you are given into moles
- Convert from moles of the known to moles of the unknown based on the coefficients in the balanced chemical reaction
- Convert from moles of the unknown to the units required
