Unit 4 Test Notes Flashcards
(108 cards)
What is a solute?
A substance that is dissolved in a solvent (ex. salt)
Solutes can be solids, liquids, or gases that are present in a smaller amount compared to the solvent.
What is a solvent?
The medium in which a solute is dissolved, often the liquid component of the solution (ex. water)
Solvents can be liquids, gases, or solids, but they are typically liquids.
Define a homogeneous mixture.
A uniform mixture of only one phase (looks the same throughout)
Examples include salt water and sugar water.
What is a solution?
A homogeneous mixture of substances composed of at least one solute and one solvent
It appears uniform throughout and does not separate upon standing.
What is a heterogeneous mixture?
A mixture where it is obvious that there is more than one substance present
Characteristics include being opaque, cloudy, and containing undissolved particles.
What is an electrolyte?
A compound that, in an aqueous solution, conducts electricity
Electrolytes are often ionic compounds that dissociate into ions when dissolved.
What is a nonelectrolyte solution?
A compound that, in an aqueous solution, does NOT conduct electricity
Nonelectrolytes are typically molecular compounds that do not dissociate into ions.
Fill in the blank: Acids form ______ solutions.
acidic
Acids increase the concentration of hydrogen ions (H+) in solution.
Fill in the blank: Bases form ______ solutions.
basic
Bases increase the concentration of hydroxide ions (OH-) in solution.
Fill in the blank: Water is known as the ______ solvent.
universal
Water’s ability to dissolve many substances is due to its polarity and ability to form hydrogen bonds.
What is dissociation in the context of ionic compounds in water?
The separation of individual ions from an ionic compound as it dissolves in water
For example, NaCl dissociates into Na+ and Cl- ions.
What does ‘like dissolves like’ refer to?
Polar substances dissolve in polar solvents; non-polar substances dissolve in non-polar solvents
This principle explains solubility behaviors based on molecular polarity.
What are hydrogen bonds?
A very strong intermolecular force formed when water is the solvent and solutes have N, O, or F lone pairs or H-N, H-O, or H-F bonds
Hydrogen bonding significantly affects the solubility of substances in water.
What is the role of London dispersion forces?
Weak intermolecular forces between non-polar substances that are responsible for dissolving non-polar solutes in non-polar solvents
These forces are significant in non-polar solute interactions.
True or False: Water is consumed during the dissociation of NaCl.
False
Water facilitates the dissociation process but remains unchanged in quantity.
What is the difference between a total ionic equation and a net ionic equation?
Total ionic equation includes all dissociated ions, while net ionic equation includes only reacting entities.
What is a total ionic equation?
A chemical equation in which all highly soluble ionic compounds are written as dissociated ions.
What criteria must a total ionic equation meet to be balanced?
- All entities on one side must be accounted for on the other side. 2. The net electrical charge must be the same on both sides.
Define spectator ions.
Ions that are not involved in a chemical reaction and do not react themselves.
True or False: Spectator ions participate in the reaction.
False.
What is a formula equation?
A chemical equation in which all compounds are represented by their chemical formulas.
What does the solubility table predict?
The solubilities of many compounds and whether an ionic compound will dissolve into ions or remain a solid.
Fill in the blank: The greater the number of _________, the more reactions occur.
collisions.
What happens when a solid dissolves into a solution?
It reduces into the smallest possible particles, creating a larger surface area and more collisions.