Name: ______________________________ Date: ___________ Block: _______
Ch 11 Fill-in
(20)
The Mole
1. Substances react according to definite ratios of ___________________________.
Balanced chemical equations tell us what the __________________ of these
particles is. If we want to know how many of these particles we have, we can
find it by measuring the__________________ .
2. Scientists have found that the atomic mass of an element contains 6.02 X 1023
atoms of that element. This number is known as ____________________________
number. This number is also equivalent to 1 ____________________ of particles.
3. The _____________________ is the SI base unit for the amount of substance. It is
defined as the number of particles in exactly 12 g of pure
________________________.
4. When dealing with moles, the simplest unit of any substance is called a
_________________________ particle.
Mass and the Mole
5. The mass of a mole of any substance is called the ______________ mass of the
substance. The molar mass of a monoatomic element is numerically equal to
the atomic mass of element, but expressed in ____________________.
6. Remember that a mole of a compound contains as many moles of each
element as are indicated by the _________________________ in the formula of the
compound. For example, a mole of ammonia (NH3) contains _________ mole of
nitrogen and _______________________ moles of hydrogen.
7. To find the molar mass of a compound, ______________ up the molar masses of
all the atoms in the representative particle.
Empirical and Molecular Formula
8. The _______________________ formula is the simplest whole-number ratio of
atoms of elements in the compound.
9. A _________________________ formula tells the exact number of atoms of each
element in a molecule or formula unit. The molecular formula is always a
whole-number _____________________ of the empirical formula. To find, you must
know the _____________________ mass of the compound and its empirical formula.
Hydrates
10. Compounds that include water in their crystal structures are called
______________________. The formula is written by adding the formula for water
to the formula for the compound, and the number of waters is shown with a
_____________________.