Chapter 10: The Mole

Question 1

Mole (Avogadro’s Number)

Answer 1

6.02 x 10^23 particles

Question 2

Subscript (Chemical Equation)

Answer 2

Denotes how many atoms of each substance in a compound

Question 3

Coefficient (Chemical Equation)

Answer 3

Denotes how many of each compound

Question 4

a.m.u. (Atomic Mass Units)

Answer 4

1 a.m.u. = 1/12 mass Carbon-12

Question 5

Formula Mass

Answer 5

Sum of atomic masses of all atoms in a formula

Question 6

Molar Mass

Answer 6

Grams (g)/mole (m)

Question 7

Grams–>Moles

Answer 7

Multiply by molar mass

Question 8

Moles–>Grams

Answer 8

Divide by molar mass

Question 9

Moles–>Particles

Answer 9

Multiply by 6.02 x 10^23

Question 10

Particles–>Moles

Answer 10

Divide by 6.02 x 10^23

Question 11

Percent Composition

Answer 11

% Element = [(number of atoms) x (atomic weight)]/(formula weight of the compound)

Question 12

Molecular Formula

Answer 12

Actual number of atoms of each type in a molecule
Ex: C6H12O6

Question 13

Empirical Formula

Answer 13

Lowest ratio of atoms in a compound
Ex: CH2O (From C6H12O6)

Question 14

Hydrate

Answer 14

Ionic material that has water incorporated in its crystalline structure

Question 15

What Happens To A Hydrate When Heated

Answer 15

The water in a hydrate may be driven off, and the crystalline structure of the material changes

Question 16

Anhydrous

Answer 16

Without water

Question 17

Finding The Formula Of A Hydrate

Answer 17

1. Find the mass of a hydrated salt
2. Heat the salt to a uniform mass
3. Find the mass lost
4. Change the grams of water lost to moles
5. Change the mass of salt remaining after heating (anhydrous salt) into moles
6. Find a mole ratio between the moles of water and moles of anhydrous salt
7. In the formula of the hydrate, use the mole ratio as a coefficient for the water