Chemistry Solutions and Reactions Quiz

Unit Conversions

• Mass conversions: milligrams (mg) to grams (g) and grams (g) to kilograms (kg)
• A milligram (mg) is 1/1000 of a gram, and a gram (g) is 1/1000 of a kilogram.
• Volume conversions: cubic centimeters (cm³) to cubic decimeters (dm³) and cubic decimeters (dm³) to cubic meters (m³)
• A cubic centimeter (cm³) is 1/1000 of a cubic decimeter (dm³), and a cubic decimeter (dm³) is 1/1000 of a cubic meter (m³).
• Amount of substance conversions: millimoles (mmol) to moles (mol)
• A millimole (mmol) is 1/1000 of a mole.
• Density conversions: grams per cubic centimeter (g/cm³) to kilograms per cubic meter (kg/m³)
• Multiplying g/cm³ by 1000 converts it to kg/m³.
• Pressure conversions: mega Pascals (MPa) to kiloPascals (kPa) and kiloPascals (kPa) to Pascals (Pa)
• A megaPascal (MPa) is 1000 kiloPascals (kPa), and a kiloPascal (kPa) is 1000 Pascals (Pa).

Simple Calculation Tasks

• Mass percentage/mass fraction: Calculate one quantity from given data.
  • Mass fraction = (mass of substance) / (mass of substance + mass of water)
  • Mass percentage = mass fraction x 100
• Molar percentage/molar fraction: Calculate one quantity from given data.
  • Molar fraction = (moles of substance)/(moles of substance + moles of solvent)
  • Molar percentage = molar fraction x 100
• Amount concentration (c): Amount concentration (c) = moles of substance / volume of solution (L)
• Density (p): Density (p) = Mass of substance / Volume of solution (L or cm³)
• Mass concentration (y): Mass concentration (y) = Mass of substance / Volume of solution (L or dm³)

Use of Mixing Equations

• Calculating solute mass from solution mass and percentage.
• Calculating mass from density and volume, or volume from mass and density.

Formulas of Inorganic Compounds

• Provides formulas for various inorganic compounds based on given ions.

Inorganic Chemistry

• Chlorine-containing disinfectants: Formulas and names.
• Chlorine-free disinfectants: Formulas and names.
• Ions causing water hardness: Mg²⁺, Ca²⁺.
• Components of bleach: NaOCl, H₂O
• Formula for chlorinated lime: Ca(OCl)₂

Kinetics

• Defining reaction rate: The change in concentration of reactants or products per unit time.
• Factors influencing reaction rates: Temperature, pressure, and concentration.
• Defining half-life: The time taken for the concentration of a reactant to decrease to half of its initial value.
• Defining catalysis: A substance that speeds up a chemical reaction without being consumed. Catalysis works by providing an alternative reaction path with a lower activation energy.
• Defining inhibition: A substance that slows down or stops a chemical reaction by interfering with a catalyst. Inhibition typically involves blocking the catalyst's active site.

Electrolysis

• Definition of electrolysis: The process of using an electric current to drive a non-spontaneous chemical reaction.
• Explanation of galvanic cells: Cells that convert chemical energy to electrical energy through oxidation-reduction reactions.
• Anode: The negative electrode where oxidation occurs, producing electrons (e⁻).
• Cathode: The positive electrode where reduction occurs, consuming electrons (e⁻).
• Oxidation: The loss of electrons.
• Reduction: The gain of electrons.

Electrolysis (continued)

• Combined electrode components (pH measurements): Glass electrode (depends on H⁺ concentration) and a reference electrode (known constant).
• Metal corrosion: The oxidation of metals due to exposure to the environment.
• Local cell formation: A galvanic cell that forms on a metal surface due to differences in its composition or environment.

Equilibria

• Mass action law (e.g., for N₂ + 3H₂ = 2NH₃): K = [NH₃]² / ([N₂] x [H₂]³) indicating the equilibrium constant based on product concentration over reactant concentration.
• Le Chatelier-Braun principle: Equilibrium shifts to counteract applied changes.
• Acid definitions (Arrhenius, Brønsted-Lowry): Different ways to classify acids based on their behavior in water (producing H⁺ ions).

Equilibria (continued)

• Ion product of water (K_w): 1.0 x 10⁻¹⁴ at 25°C and derived from the self-ionization constant of water.
• Definition of pH: The negative decadic logarithm of the hydrogen ion concentration.
• Definition of pOH: The negative decadic logarithm of the hydroxide ion concentration.
• Weak acid: Partially dissociates into its ions in solution.
• Strong acid: Completely dissociates into its ions in solution.

Buffers

• Buffer solution use: Maintain a nearly constant pH despite additions of small amounts of acid or base.
• Acidic buffer components: A weak acid and its conjugate base (salt).
• Basic buffer components: A weak base and its conjugate acid (salt).
• Hydrolyzing salts: Salts that react with water to produce an acidic or basic solution.

Acids and Bases

• Examples of weak acids: Acetic, formic, phosphoric.
• Examples of strong acids: Hydrochloric, sulfuric, nitric.
• Examples of strong bases: Sodium hydroxide, potassium hydroxide, calcium hydroxide.
• Examples of weak bases: Ammonia, lead(II) hydroxide, magnesium hydroxide.

Colloids

• Defining colloidal systems: Mixtures with particles between 1 nm and 500 nm.
• Emulsion: A mixture of immiscible liquids.
• Suspension: A heterogeneous mixture of a solid dispersed in a liquid.
• Defining adsorption: The change in concentration of a substance at a phase interface.
• Hydration: A chemical reaction in which a substance reacts with water.

Miscellaneous

• Defining chemical compound: The result of combining atoms with the same ratios.
• Defining isotope: Atoms with the same atomic number but different numbers of neutrons.
• Defining valence electrons: Electrons in the outermost shell of an atom.
• Molecules where hydrogen bonding occurs: Involves F, O, or N atoms covalently bonded with hydrogen atoms.

Thermochemistry

• Exothermic process: A process that releases heat to the surroundings, transferring thermal energy outward.
• Endothermic chemical process: A process requiring heat to proceed, absorbing thermal energy from the surroundings.
• Heat of combustion: The heat released when a substance is burned (oxidized) in excess oxygen.

Test your knowledge on solutions, mass fractions, and the properties of substances in this Chemistry quiz. It covers concepts such as weight/weight solutions, density calculations, and definitions related to acids and electrodes in galvanic cells. Perfect for students reviewing fundamental chemistry concepts!