Enthalpy And Beyond Flashcards
What is the law of conservation?
No energy can be created or destroyed
What type of reaction has a larger reactant energy than product energy?
Exothermic
What is the specific heat capacity of water?
4.18J
What is enthalpy?
Chemical energy stored in the bonds of substances
What is the formula PV=nRT used for?
It is the ideal gas law. Used to find one of the values when given the other values
What is the combined gas law and what is it used for?
P1V1/T1 = P2V2/T2. To find a new V, T, or P.
What is Hess’s Law and what is it used for?
🔼H = H(products) - H(reactants). Also written as (sum of) products - (sum of) reactants. Used to calculate the change in enthalpy.
What is change in enthalpy?
How much energy is absorbed or released in the form of heat
What can you use to calculate change in enthalpy using the formula: 🔼H = (sum of reactants) - (sum of products)?
Average bond enthalpies in formula and data booklet
What is the difference between a saturated, unsaturated, and supersaturated solution?
Saturated is when there is no more solute able to be dissolved. An unsaturated solution is when the solution contains less than the maximum amount of solute capable of being dissolved. A supersaturated solution contains more than the solute capable of being dissolved at a given temperature.
What are decimetres cubed?
Litres
What is C=n/V used for?
Calculating concentration, moles, or volume in solutions when given the other two values
What is molarity (M)
Basically just the concentration
What does R stand for in PV=nRT?
The ideal gas constant found in formula and data booklet
What is the steric number and what does it determine?
The number of other atoms bonded to the central atom. Used to determine the geometry of a molecule
What determines molecular shape?
The number of bonding atoms in the molecule
Are double bonds counted as two bonding atoms when determining shape of a molecule?
No, they are only counted as one bonding pair
What are the names of the different geometry’s in order (1, 2, 3, 4)?
1 = Linear, 2 = Linear, 3 = Trigonal planar, 4 = tetrahedral
If a molecule has a tetrahedral geometry, what are the four possible shapes in order (1, 2, 3, 4 bonding pairs)?
1 = Linear, 2 = bent, 3 = trigonal pyrimidal, 4 = tetrahedral
If a molecule has a trigonal planar geometry, what are the different shapes it may have in order (1, 2, 3 bonding pairs)?
1 = linear, 2 = bent, 3 = trigonal planar
If a molecule has a linear geometry, what will it’s shape be (1 or 2 bonding pairs)?
Always linear
What is electronegativity?
A measure of the tendency of an atom to attract a bonding pair of electrons
What are the three intermolecular forces a molecule may have?
Dispersion, dipole-dipole, and hydrogen bonds
What does a molecule require to be considered polar?
Polar bonds and unsymmetrical (resultant vector)
What do you need to remember to write when drawing a polar molecule?
Resultant vector arrows, the electronegativities, and the weird S+ and S- on each end of the molecule (S- for the end drawing the electrons to it, S+ for the end losing electrons)
What are the properties of molecules controlled by IMFs?
Boiling point (more IMF = higher), viscosity (more IMF = higher), melting point (more IMF = higher), surface tension (more IMF = more resistance to increase its surface area), and solubility (more IMF = greater solubility)
What is a solution?
A mixture resulting when a solute dissolves in a solvent
What is an aqueous solution?
A solution in which water acts as the solvent