Acids and Bases

What is the difference between strong and weak acids?

Strong acids fully ionize in solution, while weak acids partially ionize.

What does the Brønsted-Lowry theory state about acids and bases?

Acids donate H+ ions, and bases accept H+ ions.

Define a Bronsted acid.

A Bronsted acid is a proton donor.

Define a Bronsted base.

A Bronsted base is a proton acceptor.

What are polyprotic acids?

Acids capable of donating more than one proton.

What does amphiprotic mean?

Able to act as both a Bronsted acid and a Bronsted base.

Give an example of an amphoteric substance.

Water (H2O) is both amphoteric and amphiprotic.

What is the autoionization of water?

Water can ionize to form H3O+ and OH-.

What is the pH of a neutral solution?

The pH is 7.

How do you calculate pH?

pH = -log[H3O+].

What is the significance of the pKa value?

pKa = -logKa; lower pKa indicates stronger acid.

What is the effect of temperature on Kw?

Kw varies with temperature; it increases with rising temperature.

What is a conjugate acid-base pair?

Two species that differ by one H+ ion.

What is the pH of a solution containing a strong acid?

The pH is less than 7.

What is the pH of a solution containing a strong base?

The pH is greater than 7.

What is the relationship between acid strength and its conjugate base?

Stronger acids have weaker conjugate bases.

What happens to the pH when [H3O+] increases?

The pH decreases.

What is the effect of a salt containing the conjugate acid of a weak base on pH?

It makes the solution acidic (pH < 7).

What is the effect of a salt containing the conjugate base of a weak acid on pH?

It makes the solution basic (pH > 7).

What is the relationship between the strength of an acid and its dissociation constant (Ka)?

Stronger acids have larger Ka values.

What is the Arrhenius definition of an acid?

An acid donates a hydrogen ion (H+) in water.

What is the Arrhenius definition of a base?

A base donates a hydroxide ion (OH−) in water.

What is the Bronsted-Lowry definition of an acid?

An acid donates a proton (H+) in water.

What is the Bronsted-Lowry definition of a base?

A base accepts a proton (H+) in water.

What is the Lewis definition of an acid?

An acid accepts an electron pair.

What is the Lewis definition of a base?

A base donates an electron pair.

What is an acidic anhydride?

A nonmetal oxide that in water forms an acid.

What is a basic anhydride?

A metal oxide that in water forms a base.

How does the strength of hydrogen halide acids change down the column?

Strength increases down the column: HF < HCl < HBr < HI.

What is the trend for the basicity of anions?

Basicity increases with negative charge for related ions.

What is an amphiprotic substance?

A molecule or ion that can act as either an acid or a base.

What are strong acids?

Acids that dissociate completely in water and have very large dissociation constants.

Name the six strong acids.

HCl, HBr, HI, HNO3, H2SO4, HClO4.

What effect does increasing oxygen have on the O−H bond in acids?

It increases electron density opposite the H, weakening the bond and allowing for easier dissociation.

What are strong bases typically composed of?

Hydroxides or oxides of IA and IIA metals (except Mg and Be).

What is the relationship between the strength of an acid and its conjugate base?

The stronger the acid, the weaker its conjugate base.

What characterizes weak acids and bases?

They do not ionize much, leading to an equilibrium that favors reactants.

What do weak bases produce when they react with water?

They produce hydroxide ions (OH−).

What does a pH of 7 indicate about a solution?

The solution is neutral.

What is the significance of the term 'neglecting x' in acid-base equilibrium calculations?

If the initial concentration is much larger than 100Ka, x can be neglected to simplify calculations.

What does the term 'amphoteric' mean in relation to water?

Water can act as both an acid and a base.

What is the role of water in acid dissociation?

Water is crucial for facilitating the dissociation of acids.

What is the significance of the term 'sig. figs.' in reporting pH?

Report as many decimal places in pH as there are in the least accurate measurement.

What is the importance of the RICE table method in equilibrium calculations?

It helps organize initial concentrations, changes, and equilibrium concentrations.

What type of salt results from a strong base and a strong acid?

Neutral salt

What type of salt results from a strong base and a weak acid?

Basic salt

What type of salt results from a weak base and a strong acid?

Acidic salt

How do you determine if a salt solution is acidic, basic, or neutral?

Compare the strengths of the acid and base that formed the salt.

What is a Lewis acid?

A substance that can accept a pair of electrons to form a coordinate covalent bond.

What is a Lewis base?

A substance that can donate a pair of electrons to form a coordinate covalent bond.

Identify the Lewis acid and base in the reaction: H+ + H2O ↔ H3O+.

Lewis acid = H+, Lewis base = H2O

What happens to the pH when a strong acid is mixed with a weak base?

The solution becomes acidic.