CHEM FINAL

Law of Conservation of Mass

Matter is not created or destroyed; atoms are rearranged

What is a mole?

6.022 × 10²³ particles

What is molar mass?

Mass of 1 mole of a substance (g/mol)

What do you change when balancing equations?

Coefficients ONLY (not subscripts)

Goal of balancing equations

Same number of atoms on both sides

Mole ratio

Ratio of coefficients in a balanced equation

First step in stoichiometry

Balance the equation

Steps for stoichiometry

Balance → grams to moles → mole ratio → moles to grams

Limiting reactant

Reactant that runs out first and limits product

Why is limiting reactant important?

Determines how much product is made

How to convert grams → moles

Divide by molar mass

How to convert moles → grams

Multiply by molar mass

How to convert moles → molecules

Multiply by 6.022 × 10²³

Are nitrates (NO₃⁻) soluble?

Yes, always

Are Group 1 elements soluble?

Yes (Na⁺, K⁺, etc.)

Is Mg₃(PO₄)₂ soluble?

No (insoluble)

Is KBr soluble?

Yes

What is a precipitate?

Solid formed in a reaction

Neutralization reaction

Acid + Base → Water + Salt

Example of neutralization

H₃PO₄ + 3NaOH → 3H₂O + Na₃PO₄

Acid

Donates H⁺

Base

Accepts H⁺

Conjugate base

What remains after acid loses H⁺

Conjugate acid

What forms after base gains H⁺

Osmosis

Water moves to higher solute concentration

Reverse osmosis

Pressure forces water opposite direction

Organic compounds

Contain carbon

Hydrocarbons

Compounds with only carbon and hydrogen

Bond between amino acids

Peptide (amide) bond

Carbohydrates

Quick energy

Lipids

Long-term energy

Proteins

Structure + enzymes

What increases rate of dissolving?

More surface area + higher temperature

What determines mole ratios?

Coefficients in balanced equation

What must be equal in a balanced equation?

Number of atoms of each element