Exam 3

Question 1

What is a unit equation?

Answer 1

a simple statement of two equivalent quantities

Question 2

What is a unit conversion factor (unit factor) ?

Answer 2

a ratio of two equivalent options

Question 3

1 hour = 60 minutes

This is an example of?

Answer 3

A unit equation

Question 4

1 minute = 1/60th of an hour

This is an example of?

Answer 4

A unit equation

Question 5

1 hour/60 minutes = 60 minutes/1 hour

This is an example of?

Answer 5

A unit conversion

Question 6

What is the mole (mol) a measurement of?

Answer 6

The amount of a chemical substance

Question 7

Atomic Mass Units (amu) are related to what?

Answer 7

Weight in grams

Question 8

What is the equation for 1 mole aka Avogadro’s Number?

Answer 8

1 mole = 6.02 x 10^23 units

Question 9

What is the symbol for Avogadro’s Number?

Answer 9

N

Question 10

1 mole equals what?

Answer 10

Avogadro’s Number - 6.02 x 10^23

Question 11

Define Molar Mass?

Answer 11

The atomic mass of any substance expressed in grams

Question 12

What is the symbol for Molas Mass?

Answer 12

MM

Question 13

If the atomic mass of iron is 55.85 amu, what is its molar mass?

Answer 13

55.85 g/mol

Question 14

If the atomic mass of Oxygen is 16.00 amu, what is its molar mass?

Answer 14

32. 00 g/mol

- - This is because oxygen occurs naturally as a diatomic molecule (O2) so it is 2 times 16.00g

Question 15

How would you find the mass of a compound, for example, Magnesium Nitrate? Mg(NO3)2

Answer 15

1. Find the total mass of each element present
2. Add the masses
   = Answer in (g/mol)

Question 16

1 mole = ?

Answer 16

1 atom

Question 17

1 mol of ANY gas occupies how many liters at standard temperature and pressure?

Answer 17

22.4 L

Question 18

The volume occupied by ONE MOL of gas is called …

Answer 18

Molar Volume

Question 19

What is standard temperature?

Answer 19

0 degrees CELSIUS

Question 20

What is standard pressure

Answer 20

760 mmHg

Question 21

What is the formula for gas density?

Answer 21

Molar Mass in grams/ Molar Volume in liters

g/L

Question 22

What is percent composition?

Answer 22

Lists mass percent (weight) of each element

Question 23

How would you get the percentage of Hydrogen in H20?

Answer 23

• Get mass of hydrogen
• Get molar mass of H20
• Divide mass of hydrogen by molar mass of H20 & multiply by 100

Question 24

What is empirical formula?

Answer 24

The simplest WHOLE number ratio of

• ions in a forumla unit
• atoms of each element in a molecule

Question 25

If the molecular formula of Benzne is C6H6, what is its empirical formula?

Answer 25

CH

Question 26

If the molecular formula of octane is C8H18, what is its empirical formula?

Answer 26

C4H9