Final Lab Exam Practice: Chem II

Expanded structures

condensed structures

CH₃CH₃, CH₃CH₂OH

line-angle/skeletal structures

3D structures

alkene

C=C

alkyne

C≡C

cycloalkane

aromatic

aldehyde

ketone

ester

ether

alcohol

amide

carboxylic acid

functional group isomers

same molecular formula but different functional group and properties

chain isomers

isomers that have different structures

positional isomers

isomers that have R groups in different positions

geometric isomers

CH2O-C=O—R + 3NaOH > CH2OH + R-C=O O-Na+

Hard water

water that contains calcium and magnesium ions

calcium and magnesium turn it into an insoluble solid (soap scum).

Why does soap not dissolve/precipitate in hard water?

pH, foam (lather), cleansing efficiency, hardness, total fatty matter, moisture content, free alkali

What test can be done to test quality of soap?

the polar head dissolves in water and nonpolar tail that attaches to grease, allowing it to surround and wash away nonpolar substances

How does soap clean in terms of chemical structure of soap, which makes it soluble in water and able to remove non-polar substances?

monosaccharides and disaccharides such as maltose and lactose (reducing sugars) will answer positive; sucrose and polysaccharides such as starch (non-reducing sugars) will answer negative

Benedict’s test

glucose is oxidized to a carboxylic acid while Cu²⁺ is reduced to Cu⁺, forming a red precipitate

What chemical changes happen Glucose in the Benedict’s test?

acts as a reducing agent by donating electrons and being oxidized to a carboxylic acid

The aldehyde group of glucose does what?

forms a red precipitate

The calcium ions of Benedict’s solution does what?

gold, green, orange, red

What is the color change for a positive Benedict’s test?

deep blue

What is the color change for I2 test with starch?

waxes, triacylglycerols, glycerophospholipids, sphingolipids

Types of lipids

liquid state, unsaturated, linked structure, low melting point, insoluble in water

Physical properties of liquid lipids (oils)

solid state, saturated, straight structure, high melting point, insoluble in water

Physical properties of solid lipids (fats)

Bonds: single bonds only
shape: straight
melting point: high
room temp state: solid
Common sources: animal fats

Saturated lipids

bonds: at least 1 double bond
shape: linked/bent
melting point: low
room temp state: liquid
common sources: plant oils

Unsaturated lipids

brown/yellow-brown

Color change for I2 test for unsaturated lipids

Regular: heavy processing (heat); mono + poly fatty acids; lowest health value
Virgin: moderate processing; mostly mono fatty acids; good health value
Extra virgin oils: minimal processing; mostly mono (intact) fatty acids; highest health value

compare fatty acid contents of regular, virgin, extra virgin oils, and suitability for human consumption

peptide; hydrogen; disulfide (covalent), ionic, hydrogen, hydrophobic

Chemical bonds responsible for primary, secondary, tertiary structures of proteins

heat, pH, salt concentration, organic solvents, heavy metals, mechanical agitation

factors that denature a protein

Basic: accept H+, positively charged, contain amino groups
Acidic: donate H+, negatively charged, contain extra carboxyl groups

Basic and acidic amino acids

secondary, tertiary, and quaternary lose shape and function

What structures of a protein are changed in protein denaturation?

Biuret test

Which test indicates Prescence of protein?

ninhydrin test

Which test indicates presence of amino acid?

reaction rate vs enzyme concentration

linear shape

reaction rate vs substrate concentration

rate increases with [][][] until it reaches a maximum when all enzyme active sites are saturated

reaction rate vs temperature

rate increases with [][][] up to an optimum, then decreases as enzymes denature

reaction rate vs pH of enzymatic reaction

rate increases to an optimal [][][] and then decreases as [][][] changes disrupt the enzyme’s structure

bicarbonate buffer system (H2CO3 / HCO3-)

Which is the most important buffer system in human blood?

excess fat breakdown producing acidic ketone bodies, usually due to lack of insulin

Ketoacidosis is result of:

blood pH increases

How does blood pH change during hyperventilation?

equilibrium shifts to the left

During hyperventilation, HCO3- equilibrium shifts:

Breathing into a paper bag increases CO₂ in the blood, which lowers pH back toward normal

How does breathing into a paper bag help return pH levels to normal?

Blood pH increases

How does blood pH change when someone overdoses on antacids?

equilibrium shifts to the left

In overdose of antacid, which direction does equilibrium change?

soluble

Hydrocarbons (hexanes, methylene chloride) are _____ in non-polar solvents

decreases

Length of carbon chain ____ solubility in polar solvents

hydrogen bonds

Alcohols, amines, and carboxylic acids form ____ ____

Ionic: strongest, +/-
Hydrogen: moderately strong
dipole-dipole: partial +/-, weak (HCl and HCl)
van der Waals (London dispersion): weakest, present in all

Difference of intermolecular interactions

weight (g) / volume (mL)

Density formula

lower and wider range of melting point

2 most common effects on melting point if organic compound is impure