Gen Chem Exam 4

Front 1

Chemical changes refer to...

Back 1

rearrangement of atoms to form new substances.

Hint 1

— sometimes referred to as chemical reactions

Front 2

Properties of a substance which are observed through reactions are called ____.

Back 2

chemical properties

Hint 2

(like toxicity, corrosiveness, flammability, or combustion)

Front 3

How a substance interact "negatively" with biological systems?

Back 3

Toxicity

Hint 3

a chemical property

Front 4

How a substance reacts with another substance to change it to another less desirable substance?

Back 4

Corrosiveness

Hint 4

a chemical property

Front 5

____ refers to changing the arrangement of molecules or ions in space without changing the identity of the substances.

Back 5

Physical changes

Hint 5

(like their packing density from a Crystal solid to an amorphous liquid)

Front 6

Number of atoms in the reactants =

Back 6

Number of atoms of product

Hint 6

same

Front 7

Strategy to balance equations:

Back 7

1. Balance elements bound to other elements (complex compounds)

2. Balance "free" elements [e.g. (O₂) or (Al) ]

Hint 7

2 steps

Front 8

How do you change from moles to grams and vice versa?

Back 8

Using molar mass

Hint 8

g/mol

Front 9

Mass of (A) to mass of (B) by...

Back 9

1) BALANCED equation

2) convert mass (A) to moles (A)

3) use BALANCED equation to covert moles (A) to moles (B)

4) convert moles (B) to mass (B)

Hint 9

1) —

2) g (A) x (mol (A)/g (A))

I.e. "divide by molar mass"

3) if 7.2 mol C₆ H₁₄ then x by (19 mol O₂ / 2 mol C₆ H₁₄ )

4) mol (B) x (g (B)/mol (B))

I.e. "multiply by molar mass"

Front 10

The reactant that is "used up" first is the ____.

Back 10

limiting reactant

Hint 10

two words

Front 11

The smallest number of product based on available reactants indicates both the ____ and ____.

Back 11

limiting reactant; theoretical yield

Hint 11

Pizza

Front 12

The ____ (or ____) is the reactant that is completely consumed in a chemical reaction and limits the amount of product.

Back 12

limiting reactant; limiting reagent

Hint 12

Definition

Front 13

The ____ is any reactant that occurs in a quantity greater than is required to completely react with the limited reactant.

Back 13

reactant in excess

Hint 13

more than needed

Front 14

The ____ is the amount of product that can be made in a chemical reaction based on the amount of limiting reactant.

Back 14

theoretical yield

Hint 14

Definition

Front 15

The ____ is the amount of product actually produced by a chemical reaction.

Back 15

actual yield

Hint 15

Definition

Front 16

The percent yield is ____.

Back 16

. actual yield

———————— X 100%

. theoretical yield

Hint 16

an equation

Front 17

To determine the limited reactant:

Back 17

1) use BALANCED equation

2) calculate a theoretical yield for each reactant

3) the reactant with the smallest yield is the limiting reactant

(the smallest yield is also the correct theoretical yield for the reaction of given conditions)

Hint 17

3 steps

Front 18

How to find the amount left over of an excess when given the amounts of reactants?

Back 18

Use theoretical yield of product

X

(# mol of excess/ # mol product)

Front 19

Homogeneous mixture is called a ____ .

Back 19

solution

Front 20

The major component of a solution is the ____ .

Back 20

solvent

Hint 20

V in Vat as in

V in ____

Front 21

The minor component(s) of a solution is(are) the ____ .

Back 21

solutes

Front 22

In an aqueous solution, ____ is the solvent.

Back 22

water

Front 23

Instead of using qualitative terms like "concentrated" or "dilute", the amount of solute that is dissolved in a given solvent can be calculated as ____ .

Back 23

molarity (M)

Front 24

Molarity (M) =

Back 24

amount of solute (in moles)

—————————————

volume of solution (in Liters)

Hint 24

An inherent conversion factor

Also

mmols/mL

As in

Mols/1000

L/1000

Front 25

Dilution :

Back 25

M ₁ V ₁ = M ₂ V ₂

Hint 25

M ₁ is the concentration of the first solution

V ₁ is the volume removed from the first solution

M ₁ V ₁ = Mols of solute "removed"

M ₂ is the concentration of the 2nd (diluted) solution

V ₂ is the total final vol of 2nd solution

M ₂ V ₂ = Mols of solute "added" to second solution

Front 26

Electrolyte

Back 26

a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water;

Separates into cations and anions, which disperse uniformly through the solvent

Hint 26

Definition

Front 27

Soluble

Back 27

1. Most nitrate (NO₃⁻⁻) salts

2. Most salts containing the alkali metal ions (Li ⁺, Na ⁺, K ⁺, Cs ⁺, Rb ⁺) and ammonium ion (NH₄⁺)

3. Most chloride, bromide, & iodide (except those w/ Ag⁺, Pb⁺, & Hg ₂⁺ )

4. Most sulfate salts

Hint 27

Front 28

Soluble

Back 28

1. Most nitrate (NO₃⁻⁻) salts

2. Most salts containing the alkali metal ions (Li ⁺, Na ⁺, K ⁺, Cs ⁺, Rb ⁺) and ammonium ion (NH₄⁺)

3. Most chloride, bromide, & iodide (except those w/ Ag⁺, Pb⁺, & Hg ₂⁺ )

4. Most sulfate salts

Hint 28