Properties of Acids & Bases Flashcards
(34 cards)
What chemical substances are classified as?
Acidic, Basic and Neutral
What is the classification based upon?
Concentration of hydrogen ion [H+] or hydronium ions produced when the substance is dissolved in water
How are hydronium ion formed?
Hydronium ions form when the hydrogen ion bonds to the water molecule by sharing one of the electron pairs of oxygen pairs. This is called a coordinate covalent bond.
What type of bond is created when hydronium is formed?
Covalent coordinate bond: a type of covalent bond in which one atom provides the shared electron bonding pair
Name the common acids?
Vinegar, soft drink, lemon juice, car battery acid
Name some common bases.
Oven cleaners, ammonia cleanser, baking soda, washing soda
Name some neutral substances.
Pure water, sugar solution, pure alcohol solution, sodium chloride solution
Identify the name of H3Po4
Phosphoric acid
Is phosphoric acid weak or strong?
Weak
What is NaHCO3?
Sodium Hydrogen Carbonate
What are the acid-base indicators?
Natural or synthetic chemical dyes that change colour depending on the acidity of the surroundings
Are the colour changes reversible using indicators?
Yes, they are reversible.
What does the reaction of acid and base make?
Salt and water - neutralisation
Is neutralisation an exothermic reaction?
Yes, it does release energy/heat to the surroundings.
Name three examples that I can reference when told to give an application of a neutralization reaction.
- Antacid tablets
- Swimming Pool Acidity
- Soil Acidity
Explain the application of antacid tablets as a neutralisation reaction.
state the chemical equation
Our stomachs contain gastric juices, which HCl is a major compontent of it. Some ppl suffer from gastric reflux where it irritates them in their oesophagus. Neut. can be used to reduce the symptons through commerical tablets called antacids. These antacids contain a weal base such as a magnesium hydroxide, etc.
Mg(OH)2 + 2H3O+ –> Mg2+ +4H2O
Explain how swimming pool acidity is managed.
NaOCl (Sodium Hypochlorite) is added to the pool to kill bacteria, reacts with the water to produce hypochlorous acid HOCl and hydroxide ions. The pool becomes alkaline with the increase of OH. HCl is then added in small amounts to neutralise the water - maintian a pH of 7.
What is the first thing you do in a calculation equation?
Write the chemical equation
How do you calculate the enthalpy of the solution?
- Temp change
- mass
- q=mCAT
- n=CV
delta H = -q/n
What does Lavoisier’s definition?
Acids were caused by oxygen molecules when dissolved in water.
- He could not explain how metal oxides were not acidic
What does Humphry Davy’s definition state?
He found out through conducting his experiment with HCl and metals, the idea that acids could contain hydrogen.
- He could not explain why other hydrogen compounds were not acidic.
What was Arrhenius’s definition?
Arrhenius’s theory stated that the acid is a substance that ionises in solution to produce hydrogen ions, whilst a base ionises in solution to produce hydroxide ions.
What are some limitations to the Arrhenius model?
- Applies to only aqueous solns
- Accounts for substances which already have H+ and OH-
- Cannot explain how some amphoteric substances can act as both acid and a base
What did Arrhenius successfully explain?
Explained the difference between strong acids and weak acids as being due to the their different degrees of dissociation in water.
