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Chemistry, s orbital image, d orbitals image, f orbitals image, image,…

- - - - Gas
        
        Easily compressed Expand spontaneously to fill container
        
        Widely spaced molecules with much empty space between them Random motion Very weak attractions between the molecules
      - Liquid
        
        Retain volume Conform to shape of the container Able to flow Nearly incompressible
        
        Molecules tightly packed but little order Able to move past each other with little difficulty Intermolecular attractive forces relatively strong
      - Solid
        
        Retain volume retain shape Virtually incompressible Often have crystalline shape
        
        Molecules tightly packed but little order able to move past each other with little difficulty intermolecular attractive forces relatively strong
    - - Van der Waals forces ( type of interaction)
        
        Dipole-Dipole attraction
        
        Dipole -> the uneven distribution of electrons in a molecule
        due to the varying electronegativity in each atom (ex : HCl)
        
        Dipole-dipole -> attractions between molecules that possess dipole
        
        Its strength is far weaker than covalent bonds and fall off rapidly with distance
        
        Occur between molecules that have permanent dipoles (polar molecules).
        
        Hydrogen bonds
        
        When hydrogen covalently bonded to a very highly electronegative atom (F, O, or N) -> resulting in large dipole moment -> hydrogen bond
        
        Hydrogen bonds unite between those molecules and plays a crucial role in determining the shape of proteins.
        
        Occur when molecules contain N-H,F-H, and O-H bonds.
        
        London Forces
        
        The London dispersion force is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.
        
        Interaction between nonpolar substances
        
        This force is sometimes called an induced dipole-induced dipole attraction.
        
        All atoms,molecules,and ions experience these kinds of attractions. They are present in all substances
        
        Ion-Dipole and Ion-Induced Dipole Attractions
        
        Ion-dipole attractions: when ions attract the charged ends of polar molecules
        
        Ions carry a formal electrical charge that can influence other molecules through induction -> The electrical charge can cause the cloud of electron in other moleculesto be shifted -> Induced dipole
        
        The electrical charge can attract the induced dipole of other molecules -> Ion – Induced dipole attraction
        
        Occur when ions interact with polar molecules (ion-dipole attractions)
        
        Occur when an ion creates a dipole in a neighboring particle, which may be a molecule or another ion (ion-induced dipole attractions)
  - - - Properties of Matters can be influenced by the intermolecular forces, classify it by :
        
        Tightness of Packing : Compressibility and Diffusion
        
        Strength of intermolecular attractions : Volume and Shape Retention, Surface Tension, Wetting of Surface, and Viscosity
  - - - Change of state occurs when a substance is transformed from one physical state to another, and
        they always tend toward a condition of dynamic equilibrium
    - - Before system reaches equilibrium
        
        Liquid is placed in empty container -> begins to evaporate
        
        Once in gas phase, molecules collide with each other, walls of the container, and the surface of the liquid -> scattering their kinetic energies -> condensed.
        
        Before equilibrium, Rate of Evaporation >> Rate of Condensation
        
        System At Equilibrium
        
        Rate of evaporation = rate of condensation
        
        The number of molecules in the vapor will remain constant = dynamic equilibrium
    - - Melting point : The temperature at which the solid begins to change into liquid as heat added
        
        At this temperature dynamic equilibrium exists between solid and liquid states
        
        Molecules leave the solid and enter the liquid at the same rate as molecules leave the liquid and join the solid (freeze)
        
        As long as no heat is added or removed from such a solid–liquid equilibrium mixture, melting and freezing occur at equal rates
    - - At equilibrium, molecules evaporate from solid at the same rate as molecules condense from vapor
        
        Equilibrium is established when molecules sublime from the solid at the same rate as they deposit on the solid from the vapor
    - - One of the most important physical properties of liquids and solids is their tendency to undergo a change of state from liquid to gas or from solid to gas
        
        For liquids -> the change is called EVAPORATION
        
        For solids, the change directly to the gaseous state by evaporation without going through the liquid state is called SUBLIMATION .
        
        Example sublimation : Solid carbon dioxide “dry ice”
    - - The boiling point : the temperature at which the vapor pressure of the liquid equal to atmospheric pressure.
        
        strong intermolecular attractions → causing low vapor pressure → results in High boiling point
    - - q when no phase change
        q = m . s . delta T
        q when there is phase change
        q = n. delta T phase change
        
        Example :
        Liquid sodium metal is used as heat transfer material to cool nuclear reactors. How much heat is required to heat 75 g of sodium from 25°C to 515°C? The melting point of sodium is 97.8 °C; the specific heat of solid sodium is 1.23 J/g °C; the molar heat of fusion of sodium is 2.60 kJ/mol; and the specific heat of liquid sodium is 1.38 J/g °C. We will assume that the specific heats do not change with temperature
        Answer:
        Calculation of first heat (q1)
        q1 = m . s . Δt
        q1 = 75 g x 1.23 J/goC x (97.8oC-25.0oC)
        q1= 6716 J
        Calculation of second heat (q2) -> Change of phase
        q2 = n. delta H fusion
        n Na = mass/ molar mass
        = 75 g / 22.99 g.mol-1 = 3.262 moles
        q2 = 3.262 moles x 2.6 kJ/moles
        q2 = 8,481 kJ = 8481 J
        Calculation of third heat (q3)
        q3 = m . s . delta t
        q3 = 75 g x 1.38 J/goC x (515oC – 97.8oC)
        q3 = 43180 J
        Calculation of total heat (q1 + q2 + q3)
        q total = q1+q2+q3
        qtotal = 6716 + 8481 + 43180 = 58377 J
  - - - Crystal : Solid materials which atoms are arranged in a highly ordered, repeating
        pattern extending in all three spatial dimensions
        
        Crystal types:
        
        Ionic Crystals
        
        Molecular Crystals
        
        Covalent Crystals
        
        Metallic Crystals
        
        Ionic crystal
        
        Have ions at the lattice sites, the binding between them is mainly electrostatic
        
        Tend to be hard
        
        Have high melting point. Need a lot of kinetic energy to enable them entering liquid state.
        
        Example: NaCl, KCl, KF, KI
        
        Molecular crystal
        
        The lattice sites are occupied either by atoms or by molecules.
        
        Tend to be Soft
        
        Have low melting points
        
        Example : solid argon, krypton, SO2
        
        Covalent crystal
        
        Lattice positions are occupied by atoms that are covalently bonded to other atoms at neighboring lattice sites.
        
        Tend to be very hard
        
        Have a very high melting point
        
        Metallic crystal
        
        Lattice are suggested to be occupied by positive ions surrounded by negative
        ion “sea” / electron sea
        
        Conduct heat and electricity
        
        Melting points varies from high to low
        
        Hardness varies from soft to hard
        
        Stibnite (Sb2S3) with barite (BaSO4)
- - - - Hybridization is the mixing of atomic orbitals within an atom to produce new hybrid
        orbitals.
        
        The sp hybrid orbitals: the s and p orbitals yields two degenerate orbitals that are hybrids of the two orbitals.
        
        The sp2 hybrid orbitals: One s orbital and two p orbitals combine to form three sp2 orbitals.
        
        Hybridization of Carbon and Hydrogen molecule
        
        The “p” orbitals will overlap each other, resulting in Sigma (σ) bond generation
        
        There will be pi bond and sigma bond, one orbital of “p” will be left unhybridized. (in the shape of trigonal planar)
        
        Two hybridized orbitals and two unhybridized orbitals. (in a shape of linear geometry)
        
        The sp3 hybrid orbitals: One s orbital and three p orbitals combine to form four sp3 orbitals.
      - Sigma (σ) bond: the bond that is generated because of the overlapping of orbitals in head-to-head ways
        
        All single bonds are sigma bonds
      - Pi (π) bond: the bond that is generated because of the overlapping of orbitals in side-by-side ways.
        
        Can be found in double and triple bond
  - - - Bonding molecular orbitals
      - Antibonding molecular orbitals
        
        To find bond order:
  - - - Electrons fill the lowest energy orbitals that are available.
      - No more than two electrons, with spins paired, can occupy any orbital.
      - Electron spread out as much as possible, with spins unpaired, over orbitals that have the same energy.
- - - - adding a common ion decreases solubility
        
        addition of (Cl-) will shift the solubility reaction of AgCl to right, and AgCl will precipitate out
    - - on acid
        
        solubility of acid increases as the pH increase
        
        increasing the pH by adding base will make the equilibrium shift to the right
      - on base
        
        solubility of base increase as the pH decrease
        
        increasing the pH by adding base will make the equilibrium shift to the left
    - - polar solute dissolves in polar solvent and nonpolar solute dissolves in nonpolar solvent (like dissolve like rules)
    - - the formation of complex ion increases solubility of slightly soluble ionic compounds
    - - solubility generally increases with temperature, as temperature puts a stress on the equilibrium condition and causes it to shift to the right.
        
        Enthalpy total (ΔH solution) =ΔH lattice + ΔH solvation
        
        Solute undissolved + Energy ⇌ Solute dissolved
    - - as stated in Henry's Law, the solubility of a gas in a liquid is directly related to the pressure of that gas above the liquid
        
        C gas = KH . P gas
  - - - exists between undissolved solids and ionic species in solutions
        
        solids continue to dissolve and ion-pairs continue to form solids
        
        the rate of dissolution process is equal to the rate of precipitation
    - - Ksp
        
        insoluble salt does not mean totally insoluble, the very small portion of it can still be soluble
        
        in saturated solution of AgCl, the solubility product constant can be written as
        
        Ksp value determination
        
        represents the level where a solute dissolves in a solution (the more soluble a substance is, the higher the Ksp value is)
        
        can also be determined by measuring Molar Solubility
        
        moles of salt : 1 L of solvent
    - - Q (reaction quotient) = the actual concentration of ion Q is expressed in the same way was Ksp
        
        by calculating the Q value, whether a solution will result in a precipitation or not can be predicted
    - - causing one metal ion to precipitate while holding another solution due to large differences in the solubility of the salts
        
        useful for purification as we can selectively precipitate the desired ions while keep the other solution
  - - - Supersaturated Solution
        
        contains an amount of solute greater than the solute solubility
      - Unsaturated Solution
        
        contains less than the maximum amount of solute that is capable of being dissolved
      - Saturated Solution
        
        contains the maximum amount of solute that is capable of dissolving
  - - - its purpose is to
        
        separation and identification of anions
        
        separation and identification of cations
- - - - Concentration of the reactants
        
        Higher concentrations of reactants increase the reaction rate.
      - Temperature
        
        Higher Temperature increase the reaction rate
      - Ability of the reactants to meet
        
        Every reaction involved two or more reactants that have to be collided with each others
        
        area of contact determining the rate of the reaction.
        
        Homogeneous Reaction = all the reaction in the same phase
        
        Heterogeneous Reaction = all the reactants in the different phase
      - Chemical nature of the reactants
        
        reaction rates depends on the reactants nature such as atoms, molecules,
        or ions.
        
        Bonds break and new bonds form in reactions
      - Availability of catalyst
        
        Catalysts are substances that increase the rates of chemical reactions
        without being used up.
    - - Measuring Rate of Reaction
      - Reactants and products are consumed and formed at different rates
        
        Rate of reaction : The speed of a reaction independent of which reactant or product is monitored
        
        Relative rate at which substance
        is changing
        
        The rate of reaction : divide the relative rate for substance by its coefficient
      - Reaction rate is not constant throughout the reaction
        
        Instantaneous rate: rate at which a reactant is consumed or a product is formed at a specific moment in time.
        
        To find the rates of reaction at a number of
        points on the graph
        
        Independent of coefficient
        
        Initial rate of reaction: rate respects to one reaction at time zero (0)
        
        initial rate of reaction respect to whole component of reaction.
        
        Dependent of Coefficient
    - - For reaction that have multiple reactant reacting each other.
        
        A + B → products
        
        k= rate constant (temperature dependent)
        
        n and m are values that determine the order of reaction
        
        zero order reaction is a reaction that is independent of the concentration of a
        reactant
        
        No effect on the rate
        
        2 more items...
        
        first-order reaction is a reaction when the overall order is one
        
        rate increases two times
        
        2 more items...
        
        second order reaction is a reaction that the overall order is two
        
        the rate increases four times : (2)
        2
        
        2 more items...
        
        k values indicates how fast a reaction proceeds
        
        Determining Order of Reaction from Experimental Data
        
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  - - - an effective collision is one that actually gives product molecules.
      - The colliding particles must carry into the collision a certain minimum combined molecular
        kinetic energy, called the activation energy, Ea
      - Temperature provides energy for the particles
  - - - The activation energy is linked to the rate constant which discovered Svante Arrhenius -->
        Arrhenius equation
        
        Measuring Activation Energy
        
        k = rate constant, A = Frequency factor, has the same unit as k, R = gas constant in energy units (8.314 J mol-1 K-1), Ea = Activation Energy (J/mol), T = temperature (K)
        
        Rate Constants at Two Temperatures
- - - - A consistent blend of solvents and solutes occurs in a solution, driven by intermolecular forces that bring them together.
    - - Substances possess the ability to blend seamlessly in any amount, creating a uniform mixture. This happens when the attraction between the solute and the solvent matches the strength of attraction between molecules of the solvent itself or those of the solute.
    - - when two liquids that are not soluble in each other form 2 separate phases and have different intermolecular force strength of the solute and solvent.
    - - polar/ionic solvents dissolve polar/ionic solutes and non- polar solvents
        dissolve non-polar solutes.
  - - - The overall term for the encircling of a solute particle by solvent molecules is "solvation." Solubility operates on the principle of "like dissolves like," signifying that substances with similar properties tend to dissolve in one another.
    - - This phenomenon occurs when water dissolves another compound that shares similar polarity characteristics, adhering to the principle of "like dissolves like."
    - - The transition of molecules from their original phase, such as solids dissolving into liquids, necessitates energy.
      - In solids, especially in crystals, there exist lattice structures that are deemed stable owing to their strong intermolecular bonds.
      - The molar enthalpy of solution, represented as ΔHsoln, signifies the overall energy either absorbed or released when a solute dissolves within a solvent at a consistent pressure to form a solution.
    - - Step 1 involves breaking the solid lattice, which leads to an increase in potential energy (endothermic process). Step 2 involves dissolving gas in a solvent, resulting in a decrease in potential energy (exothermic process).
      - Solvation energy refers to the enthalpy change occurring when particles from one mole of solute dissolve in a solvent. If the solvent happens to be water, this specific case is termed hydration energy.
    - - When two liquids unable to dissolve in each other create distinct layers or phases due to differing strengths of intermolecular forces between their solute and solvent components.
        
        Henry's law states that the amount of gas dissolved in a liquid at a specific temperature is directly linked to the partial pressure of that gas present above the solution.
  - - - The reduction in vapor pressure due to a non-volatile solute impacts both the boiling and freezing points of the solution.
    - - Osmotic Membrane
        
        A semipermeable membrane selectively permits only the solvent molecules to pass while blocking the passage of solute particles.
      - Osmosis
        
        The movement of solvent across an osmotic membrane occurs from a region of lower concentration towards a region of higher concentration, creating a shift from a more diluted solution to a more concentrated one.
      - Osmotic Pressure
        
        The precise counteracting pressure required to halt any osmotic flow when one of the liquids involved is pure solvent.
      - Van't Hoff
- - - - the concentration of products and reactant do not change because of the two opposing reaction has the same reaction rate.
    - - Reaction can happen in both forward and reverse directions
        
        A → B (forward reaction)
        
        A ← B (reverse reaction)
    - - When the rate of the decomposing is equal to the rate of the formation reaction
    - - aA + bB ⇌ cC + dD
        
        Kc = the molar concentrations of products divided by the molar concentrations of reactants
        
        Kc > 1
        
        Equilibrium lies on the right towards the product
        
        Kc = 1
        
        Equilibrium lies midway between reactants and products
        
        Kc < 1
        
        Equilibrium lies on the left towards the reactants
      - When the direction of an equation is reversed, the new equilibrium constant is the reciprocal of the original
        
        K'c = 1/Kc
      - Homogenous Reactions
        
        Heterogenous Reactions
        
        For any pure liquid or solid, the ratio of the amount of substance to the volume of the substance is constant.
        
        in heterogeneous equilibrium law exclude pure solids or pure liquids in the and write as a value of 1
        
        Reactions only involves one phase
      - Qc (Reaction Quotient)
        
        Predict equilibrium shift
        
        Qc = Kc
        
        equilibrium (no net reaction)
        
        Qc < Kc
        
        net forward reaction (to product)
        
        Qc > Kc
        
        Net reverse reaction (to reactant)
  - - - Factors that influence equilibrium:
        
        Concentration
        
        Addition of a reactant equilibrium shifts to product
        
        Addition of a product equilibrium shifts to reactant
        
        Temperature
        
        Increasing the temperature
        
        shifts a reaction in a direction that require to release heat (exothermic)
        
        Exothermic = reaction that release heat (ΔH = -)
        
        Decreasing the temperature
        
        shifts a reaction in a direction that require to absorb heat (endothermic)
        
        Endothermic = reaction that absorbs heat (ΔH = +)
        
        Pressure
        
        Decreased volume = Increased pressure
        
        Increased pressure favour direction with less moles
        
        Catalyst
        
        A substance that increases the rate of chemical reactions without being used up.
        
        Do not affect the equilibrium constant because they only bring the system to equilibrium faster.