exam 2 chem 1230 – Flashcards
61 test answers
Unlock all answers in this set
Unlock answers 61question
| solution |
answer
| homogenous mixture of 2+ substances |
Unlock the answer
question
| solvent |
answer
| major proportion |
Unlock the answer
question
| solute |
answer
| minor proportion |
Unlock the answer
question
| colligative properties |
answer
| affected by concentration of particle the solute contirbutes to the solution |
Unlock the answer
question
| what are examples of colligative properties? |
answer
osmotic pressure vapor pressure lowering boiling point elevation freezing point depression
|
Unlock the answer
question
| colligative molality |
answer
| change in freezing point or boiling point of a solvent when solute is added |
Unlock the answer
question
| what is the equation for colligative molality? (Mc) |
answer
| Mc = i x m |
Unlock the answer
question
| how do you find molality and what are the units? |
answer
| moles of solute / kg of solvent |
Unlock the answer
question
| what is i? |
answer
| vant hoff factor; # of particles produced when a solute dissolves |
Unlock the answer
question
| what is the equation for delta T? |
answer
| delta T = Kf * Mc |
Unlock the answer
question
| what is Kf? |
answer
| the freezing point depression constant of solvent |
Unlock the answer
question
| what are the properties of lauryl acid? |
answer
| non hazardous but prolonged contact may cause skin irritation |
Unlock the answer
question
| what equipment is used in experiemnt 8? |
answer
crystallization dish graduated cylinder beaker thermometer tongs spatula hot plate |
Unlock the answer
question
| when is equilibrium established? |
answer
| when the rates of the forward and reverse reactions are equal |
Unlock the answer
question
| what are the properties of HCl? |
answer
| corrosive, irritant, use fume hood, injures eyes and skin |
Unlock the answer
question
| what are the properties of AgNO3? |
answer
| dark spots |
Unlock the answer
question
| what is the effect of raising temperature with respect to Le Chateliers principle? |
answer
| equilibirum shifts to the higher energy side |
Unlock the answer
question
| what are the reactions studied in experiment 9? |
answer
CoCl4^2- + 6 H2O -> Co(H2O)6^2+ + 4 Cl^- Fe^3+ + SCN^- -> FeSCN^2+ |
Unlock the answer
question
| when are reactants favored? products? |
answer
when K is low when K is high |
Unlock the answer
question
| what are titrations? |
answer
| stoichiometric volume of one reactant of known concentration (titrant) is required to react with another reactant of unknown concentration (analyte) |
Unlock the answer
question
| how is the concentration of the analyte determined? |
answer
| from the concentration of the titrant and stoichiometry of reaction between them |
Unlock the answer
question
| what is in the buret? |
answer
| titrant |
Unlock the answer
question
| what is in the flask? |
answer
| analyte |
Unlock the answer
question
| what is in indicator |
answer
| a substance that changes color near the equivalence point |
Unlock the answer
question
| how is an indicator chosen? |
answer
| when the equivalence point is near the end point |
Unlock the answer
question
| what is the endpoint? |
answer
| point at which the color change occurs |
Unlock the answer
question
| what should you consider when setting up a titration? |
answer
buret measured to nearest .01 mL make sure no air bubbles in buret tip condition buret fill buret below 0 mark close stopcock |
Unlock the answer
question
| what happens if you dont condition the buret? |
answer
the volume of titrant will increase the moles of analyte will be overestimated |
Unlock the answer
question
| what happens if you condition the flask with analyte? |
answer
increase in volume of titrant overestimation of moles of analyte |
Unlock the answer
question
| mass % |
answer
| moles of acid / moles of base x 100 |
Unlock the answer
question
| how do u go from moles to mmol |
answer
| 1 mol = 1000 mmol |
Unlock the answer
question
| what is the difference when doing conjugates? |
answer
| a H+ |
Unlock the answer
question
| conjugate base of an acid |
answer
| remove an H+ |
Unlock the answer
question
| conjugate acid of a base |
answer
| add H+ to base |
Unlock the answer
question
| what subsances are corrosive? |
answer
acetic Nh3 Hcl Naoh |
Unlock the answer
question
| what substances are irritants? |
answer
acetic NH3 HC; |
Unlock the answer
question
| how do u find [H3O+] given pH? |
answer
| H+ = 10^-pH |
Unlock the answer
question
| how do u find pH given [H+] |
answer
| pH = log[H+] |
Unlock the answer
question
| enthalpy |
answer
| amount of heat energy absorbed at constant pressure |
Unlock the answer
question
| entropy |
answer
| number of ways energy can be distributed in a system |
Unlock the answer
question
| system |
answer
| part of universe being studied |
Unlock the answer
question
| surroundings |
answer
| part of universe that interacts with system being studied |
Unlock the answer
question
| spontaneous |
answer
| lowers energy of system |
Unlock the answer
question
| nonspontaneous |
answer
| amount of energy supplied to cause process to occur |
Unlock the answer
question
| heat of reaction |
answer
| when reactants react completley at STP |
Unlock the answer
question
| electrodes |
answer
| metal strips |
Unlock the answer
question
| cathode |
answer
| reduction |
Unlock the answer
question
| anode |
answer
| oxidation |
Unlock the answer
question
| saltbridge |
answer
| allows ions to travel from one 1/2 cell to other |
Unlock the answer
question
| voltmeter |
answer
| calculates potential difference between oxidizing and reducing agents (mV -> V) |
Unlock the answer
question
| how do you find Ecell |
answer
| Ecell = Ecathode - Eanode |
Unlock the answer
question
| if H < 0 and S > 0 |
answer
| spontaneous |
Unlock the answer
question
| if H > 0 and S < 0 |
answer
| non spontaneous |
Unlock the answer
question
| H < 0 |
answer
| exo |
Unlock the answer
question
| H > 0 |
answer
| endo |
Unlock the answer
question
| S < 0 |
answer
| spontaneous |
Unlock the answer
question
| G > 0 |
answer
| nonspontaneous |
Unlock the answer
