Quick Review Flashcards - Click to flip and test your knowledge!
Question
According to the provided text, what is the definition of an 'Acid' in terms of ions yielded in water?
Answer
An acid is a compound which, when dissolved in water, yields hydronium ions ($H_3O^+$) as the only positively charged ions.
Question
How is a 'Base' defined in relation to its reaction with an acid?
Answer
A base is a compound which reacts with the hydronium ions of an acid to give salt and water only.
Question
What distinguishes an 'Alkali' from a general base?
Answer
An alkali is a base that is soluble in water.
Question
What is the only negatively charged ion yielded by an alkali when dissolved in water?
Answer
The hydroxyl or hydroxide ion ($OH^-$).
Question
Acids derived from plants, such as citric or acetic acid, are classified as _____ acids.
Answer
Organic
Question
Acids derived from minerals, such as $HCl$ or $H_2SO_4$, are classified as _____ acids.
Answer
Inorganic (or mineral)
Question
What is the defining characteristic of a 'Hydracid'?
Answer
It is an acid containing hydrogen and a non-metallic element other than oxygen.
Question
What is the defining characteristic of an 'Oxyacid'?
Answer
It is an acid containing hydrogen, another element, and oxygen.
Question
Define a 'Strong Acid' in terms of dissociation.
Answer
It is an acid which dissociates almost completely in aqueous solution, producing a high concentration of $H_3O^+$ ions.
Question
Why is acetic acid ($CH_3COOH$) classified as a 'Weak Acid'?
Answer
It dissociates only partially in aqueous solution, producing a low concentration of hydronium ions.
Question
What factor determines the 'Strength' of an alkali?
Answer
The concentration of hydroxyl ions ($OH^-$) present in its aqueous solution.
Question
Define 'Basicity' of an acid.
Answer
The number of hydronium ions ($H_3O^+$) that can be produced per molecule of the acid in aqueous solution.
Question
Why is Acetic acid ($CH_3COOH$) considered monobasic despite having four hydrogen atoms?
Answer
It ionises in aqueous solution to produce only one hydronium ion per molecule.
Question
In how many steps does a dibasic acid, such as $H_2SO_4$, dissociate in aqueous solution?
Answer
Two steps.
Question
Define 'Acidity' of a base.
Answer
The number of hydroxyl ions ($OH^-$) that can be produced per molecule of the base in aqueous solution.
Question
According to the Lowry-Bronsted theory, what is an acid?
Answer
An acid is a proton ($H^+$) donor.
Question
According to the Lowry-Bronsted theory, what is a base?
Answer
A base is a proton ($H^+$) acceptor.
Question
What type of chemical bond is formed when a $H^+$ ion accepts a lone pair of electrons from a water molecule to form $H_3O^+$?
Answer
A coordinate covalent bond.
Question
General Reaction: Acidic oxide + Water $\rightarrow$ _____.
Answer
Acid
Question
General Reaction: Basic oxide [soluble] + Water $\rightarrow$ _____.
Answer
Base (alkali)
Question
How are volatile acids typically prepared from salts?
Answer
By heating the salt of the more volatile acid with a non-volatile acid (like concentrated $H_2SO_4$).
Question
General Reaction: Active Metal + Dilute Acid $\rightarrow$ Salt + _____.
Answer
Hydrogen ($H_2$)
Question
What are the products of a reaction between an acid and a metal carbonate?
Answer
Salt, water, and carbon dioxide ($CO_2$).
Question
What is the 'Heat of Neutralisation'?
Answer
The amount of heat liberated when one gram equivalent of an acid or a base is completely neutralised.
Question
Which acid is used as an eye-wash?
Answer
Boric acid
Question
Which base is commonly used as an antacid to neutralise acidity?
Answer
Magnesium hydroxide
Question
What is the pH value of a neutral solution at $25^\circ C$?
Answer
7
Question
How is 'pH' mathematically defined?
Answer
$pH = -\log_{10}[H^+]$ (the negative logarithm to the base 10 of the hydrogen ion concentration).
Question
If a solution has a pH value less than 7, it is classified as _____.
Answer
Acidic
Question
What colour does Methyl Orange turn in an acidic solution?
Answer
Pink
Question
What colour does Phenolphthalein turn in an alkaline solution?
Answer
Pink
Question
In a neutral solution, what colour is Litmus?
Answer
Purple
Question
What is the primary utility of a 'Universal Indicator' over a common acid-base indicator?
Answer
It can be used to determine the strength or pH range of a solution, not just whether it is acidic or alkaline.
Question
What is the approximate pH of human blood?
Answer
7.3
Question
Define a 'Salt' in terms of hydrogen replacement.
Answer
A salt is a compound formed by the partial or complete replacement of the replaceable hydrogen ion of an acid by a metallic or ammonium ion.
Question
What is an 'Acid Salt'?
Answer
A salt formed by the partial replacement of the replaceable hydrogen ions of an acid molecule by a basic radical.
Question
Why does $HNO_3$ not form acid salts?
Answer
Because it contains only one replaceable hydrogen ion (it is monobasic).
Question
Define a 'Normal Salt'.
Answer
A salt formed by the complete replacement of the replaceable hydrogen ions of an acid molecule by a basic radical.
Question
What is a 'Basic Salt'?
Answer
A salt formed by the partial replacement of the hydroxyl radicals of a diacidic or triacidic base with an acid radical.
Question
Define a 'Double Salt'.
Answer
A salt formed by mixing saturated solutions of two simple salts followed by crystallisation (e.g., Potash alum).
Question
What is a 'Complex Salt'?
Answer
A salt that dissociates in water to yield a simple ion and a complex ion (e.g., Sodium argentocyanide).
Question
True or False: All Nitrates and Nitrites are soluble in water.
Answer
True
Question
Which four metallic Sulphates are insoluble in water?
Answer
$PbSO_4, Ag_2SO_4, CaSO_4,$ and $BaSO_4$.
Question
According to the solubility rules, most Carbonates are insoluble except for those of which three radicals?
Answer
$Na^+, K^+,$ and $NH_4^+$.
Question
What is the method used to prepare an insoluble salt from two soluble salt solutions?
Answer
Precipitation (double decomposition).
Question
Which salt preparation method involves the direct reaction of a metal and a non-metal?
Answer
Direct combination (synthesis).
Question
The laboratory preparation of $FeCl_3$ uses which general method?
Answer
Direct combination (reaction of iron and dry chlorine gas).
Question
In the preparation of $FeCl_3$, why is a fused $CaCl_2$ bulb used?
Answer
To keep the $FeCl_3$ dry, as it is highly deliquescent.
Question
Which method is used to prepare $ZnSO_4$ using zinc and dilute $H_2SO_4$?
Answer
Displacement (action of dilute acid on active metal).
Question
In salt preparation, what is the 'point of crystallisation'?
Answer
The point at which the solution is sufficiently concentrated so that crystals begin to form upon cooling.
Question
Why are lead hydroxide and sulphuric acid not used to prepare lead sulphate directly?
Answer
Because the lead sulphate formed is insoluble and forms a coating on the base, preventing further reaction.
Question
Define 'Titration' in the context of salt preparation.
Answer
The process of determining the exact volume of an acid required to neutralise a known volume of an alkali using an indicator.
Question
In a titration between $NaOH$ and $HCl$ using phenolphthalein, what colour change indicates the end point?
Answer
The pink colour just changes to colourless.
Question
What are the products when an acid reacts with a metallic sulphide?
Answer
Salt and hydrogen sulphide gas ($H_2S$).
Question
Define 'Hydrolysis of Salts'.
Answer
A reaction in which a salt reacts with water to form a base (alkali) and an acid.
Question
A salt formed from a strong acid and a weak alkali will produce a solution that is slightly _____.
Answer
Acidic
Question
Define 'Water of Crystallisation'.
Answer
The fixed number of water molecules that enter into loose chemical combination with one molecule of a salt during crystallisation.
Question
What is 'Deliquescence'?
Answer
The property of water-soluble salts to absorb moisture from the atmosphere, dissolve in it, and change into a solution.
Question
What is 'Efflorescence'?
Answer
The property of crystalline hydrated salts to lose their water of crystallisation partly or completely when exposed to the atmosphere, changing into a powder.
Question
Acid rain is defined as precipitation with a pH less than _____.
Answer
5.6