Unit 3: Solutions Outcome 2 Flashcards
(31 cards)
What are molecular compounds like generally?
neutral, not condutive, no change in litmus, pH of 7
What are ionic compounds like generally?
neutral, conductive, no change in litmus, pH of 7
What are acids like generally?
acidic, conductive, turns litmus red, pH less than 7
What are bases like generally?
basic, conductive, turns litmus blue, pH greater than 7
What are acids?
substances that dissolve in water to produce hydrogen ions
What are bases?
substances that dissolve in water to produce hydroxide ions
How are hydronium ions formed?
Hydrogen ions within an aqueous solution bonds with polar water molecules
How can hydronium ions be precisely measured?
pH meter
Are neutral solutions (pure water) completely free of hydrogen and hydroxide ions?
No, they have trace amounts of both due to very slight ionization (about 2 in a billion molecular collisions in a sample of pure water are successful in forming hydronium and hydroxide ions)
How do sig digs work with pH?
Number of decimal places
What is an acid-base indicator?
Substance that changes color when the acidity of the solution changes pH
How do indicators exist?
In two forms, each with their own distinct color
What is litmus abbreviated to?
Lt
What are the two types of litmus?
- HLt (red); protonated
- Lt - (blue); deprotonated
What is Arrhenius Theory?
- ionic compounds dissociate into separate cations and anions
- bases are ionic compounds that dissociate into a cation and hydroxide ion
- acids ionize in water to produce hydrogen ions and a hydronium ion
What is modified Arrhenius Theory?
- Acids are substances that give up a hydrogen ion in a reaction with water
- react with water to produce H3O
- in special cases the water can give up or accept hydrogen ions
- Bases are substances that can receive a hydrogen ion in a reaction with water
- react with water to produce OH
- if the formuila has a negative charge, it can accept a hydrogen ion from water (NH3 can accpet it even with a negative charge)
What are strong acids?
react completely (>99%) with water to produce hydronium ions
What are weak acids?
react incompletely with water to form relatively few hydronium ions
What is a strong base?
soluble ionic compound containing OH-
What is a weak base?
a base which reacts only partially with water to produce hydroxide ions
How are concentrated and dilute separate from pH?
concentrated- many molecules of a substance are present
dilute- less molecules of a substance are present
weak- little molecules change to ions
strong- many molecules change to ions
What is a monoprotic acid?
An acid that can only react once with water to produce a hydronium ion
What is a polyprotic acid?
An acid that can react more than once with water to produce a hydronium ion
What are monoprotic bases?
Can react only once with water to produce hydroxide ions
