ch3

Question 1

Stoichiometry :

Answer 1

The study of quantities of materials consumed and produced in chemical reactions.

Question 2

1 mole = 6.022x1023 Avogadro’s number

Question 2

Atomic mass

Answer 2

is the mass of an atom in atomic mass units (amu)

Question 3

Mole:

Answer 3

the number of atoms

Question 4

1 mol atoms = 6.022 x 1023 atoms of the elements=12gC

Question 5

atomic mass (amu) = molar mass (grams)

ex:Al= 26.9815 amu

Answer 5

I mole of Al= 6.02 x 1023 atoms = 26.9815 g (molar mass)

Question 6

Molecular mass (or molecular weight

Answer 6

) is the sum of the atomic masses (in amu) in a molecule.

Question 7

Molecular mass (or molecular weight

Answer 7

) is the sum of the atomic masses (in amu) in a molecule.

Question 8

molecular mass (amu) = molar mass (grams)

Question 9

units of molar mass are

Answer 9

grams (g/mol).

Question 10

Empirical Formula

Answer 10

formula that gives the simplest whole number ratio of atoms in a compound

Question 11

moles of limiting reactants , will يحدد how much moles of product will be produced

Question 12

Percent yield = (Actual Yield /Theoretical Yield) x 100%

Answer 12

Actual yield :is found by weighing the product obtained (experimentally)
Theoretical yield: is found by calculation.