CHEM: CHEMICAL EQUILIBRIUM (PART II) Flashcards
pH < 7, sour, turn litmus red, clear in
phenolphthalein indicator
Acids
pH > 7, bitter, turn litmus blue, pink in
phenolphthalein, slippery
base
- Substance that, when dissolved in water,
increases the concentration of hydrogen ions
Acid (+)
- Substance that, when dissolved in water,
increases the concentration of hydroxide ions
Base (-)
BRONSTED-LOWRY
- Proton donor; (proton is positive; capable of
donating proton because of the presence of
hydrogen ions) - Must have a removable (acidic) proton
acid (+)
BRONSTED-LOWRY
- Proton acceptor (negative)
- Must have a pair of nonbonding electrons
Base (-)
acts as a Brønsted–Lowry base and abstracts
a proton (H+) from the acid.
• As a result, the conjugate base of the acid and a
hydronium ion are formed.
water
From the Latin word conjugare, meaning “to join
together.”
conjugate
is a proton donor; base is proton acceptor
• Reactions between acids and bases always yield
their conjugate bases and acids.
acid
can serve as an acid and base [neutral]
water
Components of water =
= hydrogen ions and
hydroxide ions
(t or f)
water is amphoteric
true
can serve as acids or bases
Amphoteric
Chemical equilibrium equation of water (Kw);
walang denominator since hindi kasama ang
liquid (aqueous and gas lang ang kasama)
• This is referred to as ___________
autoionization.
(t or f)
Temperature is a factor
true
equilibrium favors reactants.
Small k
refers to the measurement of the
strength of an acid or base.
pH
comes to us from “portenz of hydrogen” –
portenz means strength and the hydrogen’s
chemical symbol is H.
pH
is measured using the pH scale which runs
numerically from 0 to 14.
pH
(t or f)
pH
- 0 – 7 is the region of acids (acidic solutions)
- 7 is perfectly neutral (as pure water would be)
- 7-14 is the region of bases (alkaline solutions)
true
(t or f)
• The pH scale ranges from 0-14. A pH of 7 is perfectly
neutral like pure water.
• As you go away from seven and count down toward
zero – you are getting more and more acidic.
• As you count up from seven toward fourteen – you
are getting more and more basic.
true
(t or f)
• The pH scale is based on a logarithm to the base 10
which means that each step along the pH scale
represents a change in the strength of the acid or
base by 10x
true
(t or f)
• So, for acids, an acid with a pH of 3 is ten times
stronger than an acid of pH 4. (101)
• An acid with a pH of 2 is one thousand times
stronger than an acid of pH 5. (103 = 10 x 10 x 10)
• Bases operate by the same rule of measure.
true
measures the amount of hydrogen ions released
by the acid when placed in a solution.
pH
• When an acid is placed in a solution, it releases the
hydronium or hydrogen (H+) ions and these ions
attach themselves to the water molecules (H2O) to
make the____________________
hydronium ion (H3O+).
formula of pH
pH = – log [H3O+]
measures the strength of an acid but it does
not do the same for a base.
pH
is a hydrogen ion acceptor so when you put
it in water – it doesn’t form the hydronium ion – it
forms the hydroxide ions (OH–) because it takes an
H+ from the water.
base
formula for pOH is:
pOH = – log10[OH–]
blossoms in pink or
blue, depending on soil pH. In acidic soils, the
flowers are blue; in alkaline soils, the flowers are
pink
Hydrangea macrophyll
(t or f)
- Litmus paper
▪ “Red” paper turns blue above ~pH = 8
▪ “Blue” paper turns red below ~pH = 5
true
- Often, in titration,______________ is used
[from colorless to pink in a basic medium]
phenolphthalein
is used to measure the pH of a
substance.
• is a chemical detector for hydronium ions (H3O+) or
Hydrogen ions (H+)
causes the colour of the solution to change depending on the pH.
indicator
(t or f)
• Common indicators are congo red, phenolphthalein,
methyl orange, phenol red, bromothymol blue,
bromocresol green and bromocresol purple.
true
used to measure the pH
pH meter
consists of a special measuring
probe (a glass electrode) connected to an electronic
meter that measures and displays the pH reading.
pH meter
strong acid
• Reactions involving the dissociation of strong acids
can be written with a regular_______________,
because the equilibrium lies very far to the right, i.e.
favoring the products (the dissociated ions).
forward arrow
(t or f)
- To know if it is aqueous or liquid, check if it has
charges - If it does have charges, it is an aqueous [acids or
bases] - If it is water, it is liquid
true
(t or f)
Water is not included in the acid-dissociation
equilibrium expression because the [H2O] has no
effect on the equilibrium [liquid form]
true
(t or f)
• As the Ka value of an acid increases, so does the
strength of the acid. By definition:
• strong acid: Ka > 1
• weak acid: Ka < 1
true
