Chapter 5: Stochiometry Flashcards
What is the average atomic mass
calculated from the isotopes of an element weighted by their relative abundances
What is the formula for atomic mass
(fraction of isotope n) (mass of isotope) + (fraction of isotope 2) (mass of isotope 2)`
what is the natural abundance
% of an element that is an isotope
what is mass spectrometry
technique used to measure the mass of atoms and the % abundance of isotopes
What is a mole?
counting unit
bridge from big to small
What is Avogadro’s number
6.022X10^23
What is avogadro’s number equal to
1 mole
What is molar mass
mass of 1 mole of a substance (g/mol)
How do you find molar mass
look at the periodic table
What is the molecular mass
in combination with Avogadro’s number it is used to determine the number of atoms to number of molecules
What is the empirical formula
the lowest whole number ratio of atoms
What can you use to calculate percent composition
the empirical formula
what does the % mean in % composition formula
the percentage by mass contributed by each element in the substance
how do you calculate empirical formulas
- ) mass % to grams. Assume 100 grams
- ) Grams to Moles (molar mass)
- ) Moles to empirical formula
- ) calculate the mole ratio by dividing the smallest number of moles
what is the formula obtained from % composition
the empirical formula always
what is the molecular formula
the exact number of atoms
what do the subscripts in a molecular formula represent
the whole number multiple of the corresponding subscripts in its empirical formula
what is the law of conservation of mass
whatever you start with is what you end with
what is a chemical reaction
process that leads to the chemical transformation of one set of chemical substances to another.
what are the products of the combustion reaction
CO2 and H20
What do the letters in () represent
the states
what is the symbol for gas
(g)
What is the symbol for liquid
(l)
what is the symbol for solid
(s)
