Chemistry Unit #8: Acids and Bases .............. Test on April 19, 2017 Flashcards
What is the acid name of H₃PO₄?
Phosphoric acid
Is F⁻ an acid or a base? (In terms of Brønsted-Lowry)
A base because it can accept a proton?
Define hydroxonium ion
When H⁺ reacts with water to create the hydrate H₃O⁺
H⁺ + H₂O ⇌ H₃O⁺
H⁺ or H₃O⁺ is a hydroxonium/hydronium ion
Who wrote “Experimental History of Colours”
Robert Doyle wrote “Experimental History of Colours”
Is HF a strong or weak acid/base?
Weak acid
Is HNO₂ a strong or weak acid/base?
Weak acid
Weak bases are _____ electrolytes
weak
What is the acidic name of HNO₂?
nitrous acid
What are problems associated with using indicators? 4
People do not always agree on colours
Most people only detect 1:10 colour ratio changes
Adding yellow to red will not be detectable until you have 1 part yellow to 9 parts red
Samples tested must be in solution
Adding too much will change the pH
Solutions must be clear and colourless
Coloured solutions affect indicator colour
Some indicators may react with sample
Change in composition will change colour
Strong acids are _____ electrolytes
strong
Define electrolyte
When an ionic substance creates an ion in a solution
Define Alkali
A base that is soluble in water
Metal oxides mixed with water form……?
bases
Is this chemical reaction, is the acid monoprotic or diprotic?
H₂SO₄(aq) ⇒ 2H⁺(aq) + SO₄²⁻(aq)
Diprotic because when it dissociated, the acid released 2 H⁺
For diprotic acids, the second proton released is always ____ than the first.
Weaker
When acids undergo a neutralization reaction with bases, what forms when the base is a carbonate?
Salt, carbon dioxide and water
In the chemical equation of NH₃ + H₂O ⇒ NH₄ + OH⁻, since NH₄ is the CA, that makes NH₃ the ____
Base. Water is then the acid.
A pH of 1 is ______ times stronger than a pH of 3
A pH of 1 is 100 times stronger than a pH of 3
People do not always agree on colours. Most people only detect _____ ratio colour ratio changes
People do not always agree on colours. Most people only detect 1:10 colour ratio changes
Define Strong Acids 2
Strong bases completely dissociate (split up) into ions in an aqueous solution
They release hydroxide ions in an aqueous solution
NaOH ⇒ Na⁺ + OH⁻
A pH of 1 is _____ times stronger than a pH of 2
A pH of 1 is 10 times stronger than a pH of 2
What is the points for Temperature as one of the ways we can distinguish between a strong and a weak acid?
Temperature
A reaction between an acid and a substance like a reactive metal is exothermic and the strong acid will release more energy.
Is the chemical reaction of BF₃ + NH₃ a Lewis definition or a Brønsted-Lowry definition?
a Lewis definition because the BF₃ acid’s valence electron and the NH₃ base’s valence electron is already full.
What is a pH scale? 2 - 4
A pH scale is a way of expressing the strengths of acids and bases.
Instead of using very small numbers, we just use the NEGATIVE power of 10 on the Molarity of the H⁺ (or OH⁻) ion.
A pH of 1 is 10 times stronger than a pH of 2
A pH of 1 is 100 times stronger than a pH of 3
What is the equilibrium constant of water, {H₂O(l) ⇌ H⁺(aq) + HO⁻(aq)}?
Kc = 1 * 10⁻¹⁴
All acids release _______ _____ into solution
Hydrogen ions
Brønsted-Lowry Acids and Bases contain _____-bonding pair of electrons
Non
Strong acids have _____ conductivity
strong
An acid of pH = 2 release _______ H⁺ into the solution than an acid of pH = 3
An acid of pH = 2 release more H⁺ into the solution than an acid of pH = 3
What is the Lewis definition of an Acid?
A substance that can accept an electron pair
How do you calculate pH? 1 - 3
pH = -log [H⁺(aq)]
Or When working backwards;
[H⁺(aq)] = antilog (-pH)
Or
[H⁺(aq)] = 10⁻ᵖᴴ
What are the indicators inside the Universal indicator? 4
Methyl orange
Methyl red
Bromothymol blue
Phenolphthalein
Define Arrhenius Acid
Substance that increases the concentration of H⁺ in aqueous solution.
Adding yellow to red will not be detectable until you have 1 part yellow to __ parts red
Adding yellow to red will not be detectable until you have 1 part yellow to 9 parts red
Is this chemical reaction, is the acid monoprotic or diprotic?
HCI(aq) ⇒ H⁺(aq) + CI⁻(aq)
Monoprotic because when it dissociated, the acid could only release 1 H⁺
What is the Brønsted-Lowry definition of an Acid?
A proton (H⁺) donor
The proton is really just a hydrogen atom that has lost it’s electron!
What are the 5 common examples of strong monoprotic acid?
HNO₃,
HBr,
HI,
HCIO₄
and H₂SO₄
Weak bases can react with water to form ______ ions in solution
Hydroxide
What is the Brønsted-Lowry definition of an Base?
A proton (H⁺) acceptor
The proton is really just a hydrogen atom that has gained it’s electron!
Most acids consist of hydrogen and an ______
anion
Is a Lewis acid an electrophile or nucleophile?
a Lewis acid is an electrophile because the H⁺ is positive and it is attracted to the negative compound like CI⁻
Strong acids ________ dissociate
Completely (Note the yield arrow: We use ⇒)
Most bases consist of a ______ with a hydroxide
Most bases consist of a cation (metal positively charged ion) with a hydroxide
Define Equimolar
Refers to when two solutions containe the same number of moles
Is a Lewis base an electrophile or nucleophile?
a Lewis base is a nucleophile because the OH⁻ is negative and it is attracted to the positive compound like Na⁺
Is H₂SO₄ a strong or weak acid/base?
Strong acid
Name two natural acid-base indicators
Red cabbage juice
Various teas
[H⁺] = [HO⁻] = ______ M for pure water
Kc = 1 * 10⁻⁷
When acids react with precious metals, what forms?
Nothing because precious metals do not react with the acid
Strong bases have _____ conductivity
strong
What is the Lewis definition of a Base?
A substance that can donate an electron pair
Is HBr, a strong or weak acid/base?
Strong acid
When acids undergo a neutralization reaction with bases, what forms when the base is a hydroxide?
Salt and water
Is ammonia a strong or weak acid/base?
Weak base
When acids and bases were identified by taste, what do bases taste like?
bitter