Chemistry: Molarity and Solution Concentration

Molarity and Chemical Reactions

• Molarity is a unit of measurement that quantifies the amount of a substance dissolved in a solution.
• It is defined as the number of moles of a dissolved substance (solute) per liter of solution.
• A mole is the international standard unit for quantifying the amount of a substance and is used to specify amounts of submicroscopic entities such as atoms and molecules.
• One mole equals 6.022 x 10^23 entities, known as Avogadro's number.

Molar Volume and Ideal Gas Law

• The volume of a substance per mole of that substance is its molar volume.
• At a given pressure and temperature, one mole of any gas occupies the same volume, which is 22.4 liters under standard temperature and pressure (STP) conditions.

Calculating Molarity and Moles of Gas

• To find the molarity of a solution, you need to know the liters of solution and the molarity of the key reactant.
• The formula to calculate moles of reactant is: moles = liters of solution x molarity of reactant.
• To calculate the moles of gas reacted or produced, you need to follow four basic steps: write out the chemical reaction, find the number of moles of reactant, balance the chemical reaction, and convert moles of product to liters.

Chemical Equations and Yield

• The reactants in a chemical equation are found on the left side, and the products are on the right side.
• The yield is the amount of product that is formed from the reactants.
• The limiting reactant is the reactant that yields the least amount of product.
• The molecular mass is the total atomic mass of all the elements that constitute a molecule.

Percent Composition

• Percent composition is the ratio of the total quantity of an element to the molecular mass of the compound.
• It is used to determine the empirical formula of a compound.
• The formula to calculate percent composition is: percent composition = (total amount of element / molecular mass of compound) x 100.

Dissolution and Solubility

• Dissolution is the process of a solute dissolving into a solvent to form a homogeneous mixture.
• The factors that affect the rate of dissolution include polarity, temperature, pressure, and surface area of the solute.
• Solubility is the maximum amount of a substance that can be dissolved in a solvent at a given temperature.
• A solubility curve is a graph that shows the solubility of a substance at different temperatures.

Saturated Solutions

• A saturated solution is a homogeneous mixture that contains the maximum possible concentration of a solute.
• The solubility of a substance is the concentration needed to make a saturated solution.
• The dissolution of a substance can be influenced by its polarity.

Arrhenius Acids and Bases

• An Arrhenius acid is a substance that contains hydrogen ions and donates them when dissolved in water.
• An Arrhenius base is a substance that contains hydroxide ions and accepts them when dissolved in water.
• The properties of Arrhenius acids and bases include pH values, taste, and smell.

Autoionization of Water

• Water molecules can ionize other water molecules to form hydronium ions and hydroxide ions.
• The equilibrium constant for the autoionization of water is called the Kw constant, which is 10^(-14) at 25°C.

Acidity and Basicity

• An acid is a substance that donates a hydrogen ion, while a base is a substance that accepts a hydrogen ion.
• The pH scale ranges from 1-14, with 7 being neutral.
• Strong acids and strong bases dissociate more completely in water than do weak acids and weak bases.

Coordination Compounds

• A coordination compound is a compound in which a central positively charged metal ion is covalently bound to a ligand in at least two places.
• The oxidation number refers to the positive charges that a metal ion will most stably have on its own.
• The coordination number refers to the number of atoms most stably bound to a metal ion.

Oxidation Numbers

• The oxidation number is the total number of electrons that an atom gains or loses in order to form an attraction with another atom.
• Oxidation numbers help name compounds, write formulas, and balance chemical equations.
• The rules for assigning oxidation numbers include the following:
  • The cation is written first in a formula, followed by an anion.
  • The oxidation number of a free element is zero.
  • The oxidation number of a monatomic ion equals the charge on the ion.
  • The sum of oxidation numbers in a neutral compound is zero.
  • The sum of all oxidation states in a polyatomic ion must equal the ion's charge.### Electrochemistry
• An electrochemical cell involves electron flow and a chemical reaction
• There are two types of electrochemical cells: Galvanic (Voltaic) and Electrolytic
• In Galvanic cells, the chemical reaction generates the electron flow
• In Electrolytic cells, an external source provides electrons to drive the chemical reaction
• Electrochemical cells have two electrodes: an anode (where oxidation occurs) and a cathode (where reduction occurs)
• Electrons flow from the anode to the cathode through a wire
• The electrochemical potential (E cell) measures the electrical energy of the cell
• E cell is determined by the difference in electrochemical potentials of the two electrodes

Motion

• Motion is a change in the position or direction of an object relative to another object or a frame of reference
• Motion can be measured using velocity, speed, and acceleration
• Velocity is a change in displacement over time, whereas speed is a change in distance over time
• Acceleration is a change in velocity over time
• Average velocity is a change in position divided by a change in time
• Instantaneous velocity is a position of an object divided by the time it reaches that position

Speed and Velocity

• Speed is a scalar quantity measured in meters per second (m/s)
• Velocity is a vector quantity with magnitude and direction
• Average speed is calculated by the formula: S = d / t
• Instantaneous speed requires a more sophisticated approach

Acceleration

• Acceleration is a change in velocity over time
• Falling objects accelerate at a consistent rate: -9.8 m/s/s
• The slope of a velocity-time graph represents the acceleration of an object

Mechanics

• Mechanics is the study of moving objects
• Inertia is the tendency of an object to resist changes in its state of motion
• Velocity is the speed of an object in a specific direction
• Inertia can be phrased as the tendency of an object to resist a change in velocity
• Forces cause objects to change their state of motion
• The units of force are usually expressed as Newtons

Projectile Motion

• A projectile is an object launched with an initial velocity, following a parabolic path under gravity
• Kinematic equations can be used to determine variables like final velocity, maximum height, and range
• The motion of projectiles in the horizontal and vertical directions is independent
• Equations can be used to describe projectile motion in both Y and X directions

Graphical Analysis

• Position-time graphs and velocity-time graphs can be used to describe the motion of an object
• The slope of a position-time graph represents the velocity of an object
• Analyzing the motion of an object can prove that it is moving at a constant velocity

Molarity and Chemical Reactions

• Molarity is a unit of measurement that quantifies the amount of a substance dissolved in a solution.
• It is defined as the number of moles of a dissolved substance (solute) per liter of solution.
• A mole is the international standard unit for quantifying the amount of a substance and is used to specify amounts of submicroscopic entities such as atoms and molecules.
• One mole equals 6.022 x 10^23 entities, known as Avogadro's number.

Molar Volume and Ideal Gas Law

• The volume of a substance per mole of that substance is its molar volume.
• At a given pressure and temperature, one mole of any gas occupies the same volume, which is 22.4 liters under standard temperature and pressure (STP) conditions.

Calculating Molarity and Moles of Gas

• To find the molarity of a solution, you need to know the liters of solution and the molarity of the key reactant.
• The formula to calculate moles of reactant is: moles = liters of solution x molarity of reactant.
• To calculate the moles of gas reacted or produced, you need to follow four basic steps: write out the chemical reaction, find the number of moles of reactant, balance the chemical reaction, and convert moles of product to liters.

Chemical Equations and Yield

• The reactants in a chemical equation are found on the left side, and the products are on the right side.
• The yield is the amount of product that is formed from the reactants.
• The limiting reactant is the reactant that yields the least amount of product.
• The molecular mass is the total atomic mass of all the elements that constitute a molecule.

Percent Composition

• Percent composition is the ratio of the total quantity of an element to the molecular mass of the compound.
• It is used to determine the empirical formula of a compound.
• The formula to calculate percent composition is: percent composition = (total amount of element / molecular mass of compound) x 100.

Dissolution and Solubility

• Dissolution is the process of a solute dissolving into a solvent to form a homogeneous mixture.
• The factors that affect the rate of dissolution include polarity, temperature, pressure, and surface area of the solute.
• Solubility is the maximum amount of a substance that can be dissolved in a solvent at a given temperature.
• A solubility curve is a graph that shows the solubility of a substance at different temperatures.

Saturated Solutions

• A saturated solution is a homogeneous mixture that contains the maximum possible concentration of a solute.
• The solubility of a substance is the concentration needed to make a saturated solution.
• The dissolution of a substance can be influenced by its polarity.

Arrhenius Acids and Bases

• An Arrhenius acid is a substance that contains hydrogen ions and donates them when dissolved in water.
• An Arrhenius base is a substance that contains hydroxide ions and accepts them when dissolved in water.
• The properties of Arrhenius acids and bases include pH values, taste, and smell.

Autoionization of Water

• Water molecules can ionize other water molecules to form hydronium ions and hydroxide ions.
• The equilibrium constant for the autoionization of water is called the Kw constant, which is 10^(-14) at 25°C.

Acidity and Basicity

• An acid is a substance that donates a hydrogen ion, while a base is a substance that accepts a hydrogen ion.
• The pH scale ranges from 1-14, with 7 being neutral.
• Strong acids and strong bases dissociate more completely in water than do weak acids and weak bases.

Coordination Compounds

• A coordination compound is a compound in which a central positively charged metal ion is covalently bound to a ligand in at least two places.
• The oxidation number refers to the positive charges that a metal ion will most stably have on its own.
• The coordination number refers to the number of atoms most stably bound to a metal ion.

Oxidation Numbers

• The oxidation number is the total number of electrons that an atom gains or loses in order to form an attraction with another atom.
• Oxidation numbers help name compounds, write formulas, and balance chemical equations.
• The rules for assigning oxidation numbers include the following:
  • The cation is written first in a formula, followed by an anion.
  • The oxidation number of a free element is zero.
  • The oxidation number of a monatomic ion equals the charge on the ion.
  • The sum of oxidation numbers in a neutral compound is zero.
  • The sum of all oxidation states in a polyatomic ion must equal the ion's charge.### Electrochemistry
• An electrochemical cell involves electron flow and a chemical reaction
• There are two types of electrochemical cells: Galvanic (Voltaic) and Electrolytic
• In Galvanic cells, the chemical reaction generates the electron flow
• In Electrolytic cells, an external source provides electrons to drive the chemical reaction
• Electrochemical cells have two electrodes: an anode (where oxidation occurs) and a cathode (where reduction occurs)
• Electrons flow from the anode to the cathode through a wire
• The electrochemical potential (E cell) measures the electrical energy of the cell
• E cell is determined by the difference in electrochemical potentials of the two electrodes

Motion

• Motion is a change in the position or direction of an object relative to another object or a frame of reference
• Motion can be measured using velocity, speed, and acceleration
• Velocity is a change in displacement over time, whereas speed is a change in distance over time
• Acceleration is a change in velocity over time
• Average velocity is a change in position divided by a change in time
• Instantaneous velocity is a position of an object divided by the time it reaches that position

Speed and Velocity

• Speed is a scalar quantity measured in meters per second (m/s)
• Velocity is a vector quantity with magnitude and direction
• Average speed is calculated by the formula: S = d / t
• Instantaneous speed requires a more sophisticated approach

Acceleration

• Acceleration is a change in velocity over time
• Falling objects accelerate at a consistent rate: -9.8 m/s/s
• The slope of a velocity-time graph represents the acceleration of an object

Mechanics

• Mechanics is the study of moving objects
• Inertia is the tendency of an object to resist changes in its state of motion
• Velocity is the speed of an object in a specific direction
• Inertia can be phrased as the tendency of an object to resist a change in velocity
• Forces cause objects to change their state of motion
• The units of force are usually expressed as Newtons

Projectile Motion

• A projectile is an object launched with an initial velocity, following a parabolic path under gravity
• Kinematic equations can be used to determine variables like final velocity, maximum height, and range
• The motion of projectiles in the horizontal and vertical directions is independent
• Equations can be used to describe projectile motion in both Y and X directions

Graphical Analysis

• Position-time graphs and velocity-time graphs can be used to describe the motion of an object
• The slope of a position-time graph represents the velocity of an object
• Analyzing the motion of an object can prove that it is moving at a constant velocity