Guide To Calculating Chemical Quantities printable pdf download

Guide To Calculating Chemical Quantities

Guide to Calculating Chemical Quantities

The Mole:

 A mole of any compound contains 6.02X 10

particles; Avogardo’s Number

 1 mol = 6.02 X 10

 The subscripts in a formula indicate the number of moles of each element in one

mole of the compound

Guide to Calculating the Atoms or Molecules of a Substance:

(1 step

problem)

STEP 1: Determine the given number of moles

STEP2: Write a plan to convert moles to atoms or molecules

STEP 3: Use Avogardo’s number to write the conversion factors

STEP 4: Set up the problem to convert given moles to atoms or molecules

Example:

 Use Avogardo’s number to calculate the following: The number of Ca atoms in

3.00 mol of Ca

Given = 3.00 mol Ca

Unknown: atoms of Ca

Conversion Factor: 6.02 X 10

1 mol

3.00 mol Ca

6.02 X 10

atoms

= 1.81 X 10

atoms

1 mole

Molar Mass:

 The molar mass of an element is numerically equal to its atomic mass in grams

 The molar mass (g/mol) of a compound is determined by multiplying the molar

mass of each element by its subscript in the formula and adding the results

together

Guide to Calculating Molar Mass

STEP 1: Obtain the molar mass of each element (the atomic mass from the

periodic table)

STEP 2: Multiply each molar mass by the number of moles (the subscript) in the

formula

STEP 3: Calculate the molar mass by adding the masses of the elements together

Example:

Guide To Calculating Chemical Quantities