Chemistry - Moles Test

mole

an amount, defined as the number of carbon atoms in exactly

6.02×10^23

Avogadro’s number

Representative Particles

smallest pieces of a substance

molecule

Representative Particles for a molecular compound

formula unit

Representative Particles for a ionic compound

atom

Representative Particles for an element

molar mass

generic term for the mass of one mole of any substance (expressed in grams/mol)

gram molecular mass

molar mass for molecules

gram formula mass

molar mass for ionic compounds

gram atomic mass

molar mass for elements

gases

Many of the chemicals we deal with are in the physical state as:

temperature and pressure

What two things effect the volume of a gas

22.4L, molar volume

At STP, 1 mole of any gas occupies a volume of ____________, called the ___________

mass / volume

density = what / what

g/L

for the density of a gas the units will be:

density x volume

mass = what x what

accepted value

the correct value based on reliable references

experimental value

the value measured in the lab

error

• accepted value – exp. value

  • Can be positive or negative

percent error

the absolute value of the error divided by the accepted value, then multiplied by 100%

empirical formula

the lowest whole number ratio of atoms in a compound

molecular formula

the true number of atoms of each element in the formula of a compound

empirical

Formulas for ionic compounds are ALWAYS _______

moles

A formula is not just the ratio of atoms, it is also the ratio of ________

percent composition

We can get a ratio from the __________