Chapter 7.3 and 7.4

Question 1

The mass of an atom, molecule, or ion is called what?

Answer 1

formula mass (measure in amu)

Question 2

The mass of the mole of a substance is called what?

Answer 2

molar mass (grams)

Question 3

1 mole equals how many particles?

Answer 3

6.022 × 10^23

Question 4

What is the order that you convert masses in?

Answer 4

g – moles – molecules – atoms
molar av’s # subscript

opposite

atoms – moles – grams

Question 5

What is the Empirical formula?

Answer 5

The Empirical formula is a compound’s formula in it’s lowest whole number ratios.

Question 6

Are ionic compounds already at their lowest whole number ratios?

Answer 6

Yes

Question 7

Are covalent compounds already at their lowest whole number ratios?

Answer 7

No

Question 8

What are the steps to find the Empirical Formula?

Answer 8

1. Convert to moles
2. Divide each number by the smallest mole number
3. Multiply by a factor to get a whole number ratio

Question 9

What is the Molecular formula?

Answer 9

The molecular formula is a compound’s formula at it’s exact composition. It IS NOT reduced!

Question 10

To find the Molecular formula, what do you need?

Answer 10

you need the molar mass of the compound

Question 11

When finding the molecular formula of a hydrate, one of the numbers will always be _.

Answer 11

1

Question 12

What is Molarity?

Answer 12

Molarity describes the concentration of a substance.

Question 13

What is molarity’s formula?

Answer 13

moles of solute (stuff being dissolved)

Question 14

What can you abbreviate Molarity as?

Answer 14

M, mol/l, molar

Question 15

What is good for prepping a solution?

Answer 15

A volumetric flask

Question 16

________ decrease concentrations by adding water.

Answer 16

Dilutions decrease concentrations by adding water.

Question 17

What is the solvent in a dilution?

Answer 17

H20

Question 18

What is the equation for Molarity for dilutions?

Answer 18

Molarity(i)Volume(i) = Molarity(F)Volume(F)

MiVi = MFVF

Question 19

What is molality?

Answer 19

Molality is a way to express the concentration of a solution.

Question 20

What is the formula for molality?

Answer 20

moles of solute

kilograms of solvent (H20)

mol/kg

Question 21

What can you abbreviate Molality as?

Answer 21

m, mol/kg, molal

Question 22

Is molarity temperature-dependent?

Answer 22

Yes (technically)

Question 23

Is molality temperature-dependent?

Answer 23

No

Question 24

What is the formula for percent composition?

Answer 24

(mass X)

(total mass) x100

Question 25

When finding the molecular formula, you divide the molar ____ by the empirical's ____.

Answer 25

When finding the molecular formula, you divide the molar mass by the empirical's mass.

Question 26

When finding the significant figures for a problem's answer, you should refer to the what?

Answer 26

original numbers of the problem

Question 27

A substance should be diluted by adding ____ to _____, not the other way around.

Answer 27

A substance should be diluted by adding acid to water, not the other way around.

Question 28

When should the ratio of an element to it's compound be added to the stoichieometry equation?

Answer 28

The ratio should be added when the question asks for the amount of said element.