Chemistry: Acids, Bases, Energy, and Reactivity

Comprehensive practice questions covering acids, bases, thermochemistry, reaction kinetics, electrochemistry, metallurgy, organic chemistry, and radioactivity as radioactivity.

According to the Arrhenius definition, how is an acid defined?

A substance that dissolves in water to form $H^+/H_3O^+$ as the only positive ion/cation.

What is the Bronsted-Lowry definition of a base?

A base is a proton acceptor.

In a Bronsted-Lowry reaction, what is formed when an acid donates a proton?

A conjugate base.

Why do acids and bases only show characteristic properties in water and not in solvents like methylbenzene?

Because they do not dissociate or ionize into free ions in non-polar solvents; they remain in a molecular state.

Define a strong acid or base.

One which is fully, wholly, or completely dissociated into many free $H^+$ or $OH^-$ ions.

What is an amphotellic substance?

A substance that exhibits properties of both acids and bases and can react with both.

Which three metal oxides are identified as being amphotellic in the text?

Zinc(II) oxide ($ZnO$), Lead(II) oxide ($PbO$), and Aluminium(III) oxide ($Al_2O_3$).

What is the basicity of an acid?

The number of ionizable or replaceable hydrogen atoms in an acid molecule.

Identify the property of a salt that absorbs water from the atmosphere without forming a solution.

Hygroscopy.

What name is given to the process of identifying an unknown salt based on unique qualities like precipitate color?

Qualitative analysis.

Define the solubility of a salt.

The maximum mass of salt that dissolves in $100g$ of solvent at a specified temperature.

What are the two common types of water hardness and their causes?

Temporary hardness (caused by calcium or magnesium hydrogen carbonates) and permanent hardness (caused by calcium or magnesium sulphates(VI)).

What is the SI unit of energy used in thermochemistry?

The Joule ($J$).

Describe an exothermic reaction in terms of temperature change and enthalpy ($\Delta H$).

It cause a rise in temperature, and the enthalpy change is negative ($-\Delta H$).

State Hess’ law of constant heat summation.

The total enthalpy/heat/energy change of a reaction is the same regardless of the route taken from reactants to products at the same temperature and pressure.

According to the collision theory, what are collisions that initiate a chemical reaction called?

Successful, fruitful, or effective collisions.

What is Activation Energy ($E_a$)?

The minimum amount of energy which reactants must overcome before they react.

State Le Chatelliers Principle regarding dynamic equilibrium.

If a stress or change is applied to a system in dynamic equilibrium, the system readjusts or shifts so as to remove, reduce, counteract, or oppose the stress or change.

Define oxidation and reduction in terms of electron transfer.

Oxidation is the donation, loss, or removal of electrons. Reduction is the gain, acceptance, or addition of electrons.

What are the standard conditions for measuring electrode potential ($E^{\theta}$)?

Temperature of $298K$ ($25^{\circ}C$), pressure of $101300\,Pa$, and a concentration of $1M$ for ions.

State Faradays 1st law of electrolysis.

The mass or amount of substance liberated, produced, or used during electrolysis is directly proportional to the quantity of electricity passed or used.

What is the chief ore used in the extraction of Aluminium?

Bauxite ore (hydrated aluminium oxide, $Al_2O_3 \cdot 2H_2O$).

During the extraction of Iron in the blast furnace, what is the role of limestone?

It decomposes to form quicklime ($CaO$), which reacts with silica and alumina impurities to form slag.

What is the general formula for the homologous series of alkanols?

$$C_nH_{2n+1}OH$$

Name the biological catalyst in yeast used to convert glucose into ethanol.

Zymase.

Describe the process of saponification.

The reaction of an ester (fat or oil) with a concentrated alkali to form a sodium or potassium salt (soap) and glycerol.

What is the difference between addition and condensation polymerization?

Addition polymerization joins unsaturated monomers without losing any atoms; condensation polymerization joins monomers by eliminating a simple molecule like $H_2O$ or $HCl$.

What is a nuclide?

An atom with defined mass number (protons and neutrons), atomic number, and definite energy.

Describe the characteristics of an alpha ($\alpha$) particle.

It is positively charged, has a mass number of $4$ and atomic number of $2$ (equal to a Helium nucleus (${ }^{4}_{2}He^{2+}$)), and has low penetrating power.

Define nuclear fission.

The process where a fast-moving neutron bombards a heavy unstable nuclide, releasing lighter nuclides, daughter neutrons, and large quantities of energy.