Midterm 3: Acids and Bases Flashcards
What is the Cirtic Acid structure formula?
What is Malic acid structure formula?
What are bases and acids behaviours in response to H+ and OH - in aqueous solutions?
Acids increase in hydrogen in H20, bases also increase in OH- in H2O
How many interactions of H-Bonds are in H9O4+
The core structure contains three primary hydrogen bonds due to 𝐻3𝑂 + H3O + interacting with water.
H20 generally donates a proton and becomes what?
OH-
What is the relationship between acids and bases in H2O?
Acids must have a hydrogen to give away while bases must have a lone pair of electrons for acids to react with
What is the conjugate base of water?
OH- when water is the acid in the reaction and X- of Hx
Example: H3O+ is conjugate acid of H2O
Hydrogen sulphite is amphiprotic: What is the equation when its an acid? What is the equation when it acts as a base?
For lewis acid and bases, what is required for a substance to be a proton acceptor?
Must have a pair of electrons. Lewis acids are electron pair acceptors and lewis bases are electron pair donors.
What are examples of lewis acids?
H+ and CO2. CO2 is special because it is a molecule with multiple bonds but it behaves as a lewis acid
Are metal ions acidic or basic?
Acidic. Metal ions attract unshared molecules.
What occurs when your throw a metal ion in water?
Metal ion acts as the lewis acid and H2O acts as the base.
Electron density goes away from oxygen in water. this causes the hydrogen bond of water to become more polarized.
What is the relationship between bases and acids?
Acids are proton donors and bases are proton acceptors.
A very weak acid will have a strong conjugate base
A very weak base will have a strong conjugate acid.
What are the three rules regarding acid strength?
- Strong acids completely transfer their protons to H2O and so their conjugate have no tendency to be protonated in H2O
- Weak acids partially dissociate in H2O so they exist as a mixture of molecules and ions
- Those with no acidity are substances like CH4 but those conjugate bases are strong (forms OH-)
How does H2O work in the presence of an acid and a base?
In the presence of acid H2O is a proton acceptor (H3O+) but in the presence of a base, it donates a proton (H2O-)
What is Kw at 25 degree’s celcius?
Kw = 1.0 x 10 ^ -14
What is H+ at room temperature with an OH- 0.010 M
Freshly squeezed apple juice has a pH of 3.76. What is the concentration of H+?
In acid and bases, the strength of acid depends on?
- Polarity of the bond, a molecule with H will transfer a proton only if H-X bond is polarized.
- Strength of the bond
- Stability of the conjugate bases “X-“ the greater the stability, and the stronger the acid
If the temperature increases in water, what is the effect to the pH?
The pH will decrease as heat increases, as does H+
What occurs when electron density goes to “Y”
OH bonds become weaker and more polar, therefore a loss of H+ acid will occur.
This happens because the conjugate base is the anion and stability of base increases.
What is the relationship between electronegativity and acid?
Strength of the acid increases as additional electronegative atoms are attached to the central atoms
Is perchloric acid stronger than HOCl?
Perchloric acid (HClO₄) is significantly stronger than hypochlorous acid (HOCl) due to its very low pKa, high oxidation state of chlorine, and resonance stabilization of the conjugate base.
Whats the pH of 0.040M solution of HClO4?
So, a 0.040 M HClO₄ solution has a pH of approximately 1.40.
0.30 M NaOH is 0.30 M NA+ and 0.30M OH-, What is the pH of a 0.0011 M solution of Ca(OH)2?
0.0011 M Ca(OH)₂ solution has a pH of approximately 11.34.
Are most acids strong or weak acids?
Most acids are weak acids. this means its not easy to find equilibrium because they don’t completely disassociate. They only partially ionize in solution, we use Keq constant to expresses the extent of ionisation.
What is the Ka of 0.10 M of formic acid with a pH of 2.38 at 25 degrees celcius?
K a =1.8 × 10^−4
In a weak acid problem what will the exponent generally be?
The exponent will generally be between X^-3 and X^-10
Anything that has a lone pair of nitrogen electons is generally what?
A weak base
What are the two classes of bases?
- Contains neutral species with non-bonding pair of electrons serve as proton acceptor
- Anions of weak acids
What is the simplest organic amine?
CH4NH2 - Methylamine
