Chemistry Quiz on Oxidation and Acids

The process where a substance gains electrons, resulting in a decrease in oxidation number.

A substance that causes another substance to be oxidized, itself being reduced.

The oxidation number of nitrogen in the nitrate ion (NO3-) is +5.

In the unbalanced equation, Al(s) + Cl2(g) -> AlCl3(s), chlorine is the oxidizing agent. Chlorine gains electrons, becoming Cl- ions in AlCl3.

The pH of the solution will become acidic when ammonium chloride (NH4Cl) is dissolved in water. This is because the ammonium ion (NH4+) acts as a weak acid, donating protons to water molecules, increasing the H3O+ concentration and thus lowering the pH.

The equilibrium constant for the ionization of an acid (Ka) multiplied by the equilibrium constant for the ionization of its conjugate base (Kb) is equal to the ion product of water (Kw). Ka * Kb = Kw

The pH of a 0.100 mol/L solution of Ca(OH)2 with a pOH of 0.700 is 13.3.

A stronger acid has a weaker conjugate base. The weaker the acid, the stronger its conjugate base.

A chemical reaction where one mole of a compound is formed from its elements in their standard states.

The enthalpy change that occurs when one mole of a compound is formed from its elements in their standard states.

A process that involves breaking bonds and forming new bonds.

The amount of energy required to break one mole of a specific bond, usually expressed in kJ/mol.

A method used to estimate the enthalpy change (ΔH) of a reaction by calculating the difference between bond energies of reactants and products.

A reaction where the enthalpy change (ΔH) is negative, indicating that energy is released during the reaction.

A reaction where the enthalpy change (ΔH) is positive, indicating that energy is absorbed during the reaction.

A way to calculate the enthalpy change of a reaction using the enthalpy changes of known reactions that can be added or subtracted to obtain the desired reaction.

Heat is released when a substance undergoes combustion. The amount of heat released is directly proportional to the mass of the substance and its enthalpy of combustion.

Thermal energy flows from a hotter object to a cooler object. In this case, the hot copper metal will transfer heat to the cooler water.

The amount of energy required to raise the temperature of a substance is directly proportional to the mass of the substance, the specific heat capacity of the substance, and the change in temperature.

The heat absorbed or released during a chemical reaction measured in a coffee cup calorimeter.

The IUPAC name for a carboxylic acid is formed by combining the name of the parent alkane with the suffix -oic acid.

The IUPAC name for an ether is formed by naming the alkyl groups attached to the oxygen atom followed by the word 'ether'.

Brønsted-Lowry acids are substances that donate protons (H+ ions) in a chemical reaction.

A buffer system resists changes in pH when small amounts of acid or base are added. When an acid is added, the equilibrium shifts to the left, removing H+ ions and minimizing the pH change.

Le Chatelier's Principle states that a system at equilibrium will shift to relieve stress. When pressure is increased in the syringe, the system shifts to the side with fewer moles of gas. In this case, the equilibrium shifts to the right (clearer) as 2 moles of NO2 react to form 1 mole of N2O4.

The equilibrium constants for the forward and reverse reactions are reciprocals of each other. Their magnitude depends on the position of the equilibrium.

The trial ionic product (Q) compares to the solubility product constant (Ksp) to determine if a precipitate will form. If Q is greater than Ksp, the solution is supersaturated, and a precipitate will form. The equilibrium shifts left to alleviate this.

The Ksp (solubility product constant) represents the equilibrium constant for the dissolving of a sparingly soluble ionic compound. It indicates the maximum concentration of ions that can exist in a solution before precipitation occurs.

The magnitude of the equilibrium constant (K) indicates the extent to which a reaction proceeds to completion. A large K indicates a reaction that favors product formation, while a small K indicates a reaction that favors reactant formation.

The equilibrium constant (K) is a value that indicates the relative amounts of reactants and products present at equilibrium. It is temperature-dependent and a measure of the tendency of a reversible reaction to proceed to completion.

Factors that affect the rate of a chemical reaction. These include:

1. Concentration: Increasing the concentration of reactants leads to more frequent collisions and therefore a faster reaction rate.
2. Temperature: Raising the temperature increases the kinetic energy of molecules, leading to more energetic collisions and a faster reaction rate.
3. Surface Area: Increasing the surface area of reactants (like a solid) provides more contact points for reaction, increasing the rate.
4. Catalysts: Catalysts are substances that speed up reactions without being consumed. They provide alternate reaction pathways with lower activation energy.

The rate at which reactants disappear or products appear in a chemical reaction. It is typically expressed in units of concentration change per unit time (e.g., mol/L·s).

A reaction where the reactants and products are in different phases (solid, liquid, gas). For example, a solid reacting with a liquid or a gas reacting with a solid.

The rate of a chemical reaction is directly proportional to the product of the concentrations of the reactants, each raised to a power. The powers are called the order of the reaction.

For example, if the rate law is rate = k[A]^2[B], then the reaction is second order in A and first order in B.

The enthalpy change that occurs when one mole of a compound is formed from its elements in their standard states under standard conditions (298 K and 1 atm).

The enthalpy change for a reaction that is calculated by subtracting the sum of the enthalpies of formation of the reactants from the sum of the enthalpies of formation of the products.

ΔHrxn = ΣnΔHf(products) - ΣmΔHf(reactants) Where n and m are the stoichiometric coefficients in the balanced chemical equation.

A primary alcohol contains the hydroxyl group (-OH) attached to a carbon atom that is bonded to only one other carbon atom.

The reaction that forms alcohols by adding water (H2O) to an alkene is called a hydration reaction. The water molecule breaks apart, with the hydrogen atom (H) attaching to one carbon of the double bond and the hydroxyl group (OH) attaching to the other carbon.

A compound with the formula C5H8 where a methyl group (CH3) is attached to the fourth carbon atom of the cyclopentene ring.

Alcohols are typically made by the addition reaction of water and alkenes. The double bond in the alkene breaks, and the water molecule adds to the carbons of the double bond.

A phenyl group is a benzene ring where one hydrogen atom is removed. It behaves as a substituent group attached to a hydrocarbon, creating aromatic compounds. It's like a benzene ring playing the role of an add-on.

This molecule contains a benzene ring with two hydroxyl groups (-OH) attached to adjacent carbon atoms on the ring. It is a type of aromatic diol.

The IUPAC name for the compound is 2-ethoxyethane. It describes an ether with an ethoxy group (CH3CH2O-) attached to the second carbon of an ethane chain.

When an alcohol has two hydroxyl groups (OH) attached to different carbon atoms within the same chain, it is designated using the suffix '-diol'