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AP Chemistry 2

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. How does the melting point of a mixture compare to the MP of a pure substance?

2. Does reactivity increase/decrease going down group 1 and group 17?
Pour liquids using a funnel or down a glass rod
Increase - the dissociation of water is endothermic so increasing T favors forward direction - thus more ions.
Increases down group 1 decreases down group 17
Tetrahedral

3. Ions are not ______.
buret - pipette - pipette filler - Erlenmeyer flask - volumetric flask
atoms
+4 and +2 (+4 dominates top of group and +2 at bottom of group)
Supercooling can occur when cooling a solvent or solution. It occurs when there's a dip and then a rise back up to the melting point on a cooling curve.

4. A geometric (or cis-trans) isomer exists due to.....
Acids; HCOOCH3 is an ester
P2O5
Lack of rotation of groups around a double bond. (cis has groups on same side - trans on opposite sides)
Reduction always takes place at the cathode (RED CAT) In both types of cell!

5. Name C7H16
H2PO4?
Heptane
Two forms of the same element (same Z) with different # of neutrons and similar chemical properties
[A?]/[HA] x 100 or [BH?]/[B] x 100

6. For what types of substances does the solid/liquid equilibrium line on a phase diagram slope LEFT?
Nothing
Increases for endo - (becomes more soluble) decreases (becomes less soluble) for exo.
zero-th: decreases - first: constant - second: increases
water and substances with (s) less dense than

7. ____ is a Lewis acid - since it can accept a lone pair - completing its stable form - which requires two electrons.
Q=It (time in seconds)
Initiation energy (NOT Ea)
Sulfur
H+

8. What things should you remember to do when collecting gas over water?
by electrolysis
allow for the vapor pressure of water and make sure to level levels
yellow
Group I metals (soft metals) are stored under oil

9. ________ are Lewis bases - because they can donate a lone pair of electrons.
Ions go through the salt bridge - electrons go through metal wires in the external circuit
O2 needs 4F/mol H2 needs 2F/mol
OH- and NH3
They decrease (or could be the same if the solid has ONLY JUST disappeared)

10. Acids + Carbonates (bicarbonates) make?
Salt - Carbon dioxide and water.(latter also known as carbonic acid H2CO3)
#ligands=charge x2
Concentration
They decrease (or could be the same if the solid has ONLY JUST disappeared)

11. What value of R do you use for thermo calculations? gas calculations?
Increases down group 1 decreases down group 17
Thermo: R=8.31J/mol/K - gas calculations: R=.0821 L atm/mol/K or 62.4L mmHg/mol/K
Sigma bonds are stronger than pi bonds
?H formation of an element in standard state=0

12. Is the standard entropy (S°) of an element zero?
But S° of element is not zero (except at 0K)
Transition element compounds (except if it has a full or empty d shell)
CrO4²?
At half equivalence - pH=pKa

13. During a titration what is present in the beaker at the equivalence point?
?H formation of an element in standard state=0
A salt solution.
Salt + water.
Identity and purity (impure compounds usually have broad & low melting points)

14. What is the formula for alkenes?
chemically (ex: with carbon)
CnH2n
Q=It (time in seconds)
oxidizing - (F2 is the best) - reducing (ex: Li - Na).

15. chlorate
ClO3?
Both electrons come from the same atom (just as good as a regular bond)
Filtration
ion pairing

16. What do group I/II metal oxides and acids form?
Experimental mass/theoretical mass X 100
Current - time and charge on ion (moles of e used in half cell reaction)
Two amino acids joined together; many amino acids joined together; lots of amino acids joined together
Salt and water

17. Give an example of a concentrated weak acid.
Identity and purity (impure compounds usually have broad & low melting points)
Glacial acetic acid
1) Add together a weak base with a salt of that base made with a strong acid. (or visa versa) 2) by partially neutralizing a weak base with a strong acid or weak acid with a strong base. (Ex: 0.2 mol NH3 + 0.1 mol HCl)
Synthetic condensation polymer (aka a polyamide)

18. What is the general formula for an alcohol?
ROH
They have high ionization energies (due to high nuclear charge and no shielding) and cannot add electrons due to full valence shell
HClO4
blue

19. What happens to the ion concentrations of a saturated solution when it is diluted and no solid solute remains?
Trigonal pyramidal
bright yellow
Ksp = 27s4
They decrease (or could be the same if the solid has ONLY JUST disappeared)

20. When a cell is 'flat' a.k.a 'reached equilibrium' - what is its ?G value?
small size and high charge
zero
blue (BTB)
NO2 and SO2 are very soluble - CO2 and O2 are somewhat soluble

21. What is the relationship between Rate and Molar Mass for two gases? Velocity and Temperature? Energy and Temperature?
yellow
Suniverse increases for spontaneous processes
NO3?
r1/r2=(M2/M1)^½ - v1/v2=(T1/T2)^½ - E1/E2=T1/T2

22. What process do you use to obtain the solute from a solution?
Evaporation
Disulfur dichloride
Add acid to water so that the acid doesn't boil and spit
H2O + CO2 (it decomposes readily)

23. Is the freezing of ice endothermic or exothermic?
CO3²?
Exothermic
CnH2n+1 often designated 'R' ex C3H7 is propyl
Increase - the dissociation of water is endothermic so increasing T favors forward direction - thus more ions.

24. lead compounds
1. Rinse the buret/pipette with deionized water - 2. Rinse the buret/pipette with the solution you plan on filling the buret/pipette with.
Insoluble except nitrate and acetate
WA/SB: pH>7 SA/WB: pH<7 SA/SB: pH=7
CrO4²?

25. dichromate
The benzene ring (or more correctly the phenyl group - C6H5)
Cr2O7²?
Disulfur dichloride
Clear

26. What do you do to Keq when you combine 2 reactions - reverse an equation - or halve coefficients?
But S° of element is not zero (except at 0K)
Making sigma bonds and holding lone pairs
Check for air bubbles in the buret and remove the buret funnel from the buret
Combine: multiply Keq - reverse: 1/Keq - Halve coefficients: Keq^(1/2)

27. How many normal boiling points and boiling points are there?

28. What is Ksp in terms of molar solubility ('s') for an electrolyte AB3 or A3B?
Increases for endo - (becomes more soluble) decreases (becomes less soluble) for exo.
Ksp = 27s4
yellow
No - it depends on the number of ions produced on dissolving.

29. What is the charge on a chlorine atom?
ROR
benzene is less reactive than alkenes
zero
Equivalence point is the titrant volume when the moles of acid and base are stoichiometrically equal; end point is the titrant volume when the color of the indicator permanently changes. If you choose the correct indicator - they should occur at the

30. What are two substances that sublime at 1 atm when heated?
zero
basic
Purple
Iodine and CO2 (dry ice)

31. What do group I/II metal oxides plus water form?
Big K=kf/kr
bases
Heptane
Supercooling can occur when cooling a solvent or solution. It occurs when there's a dip and then a rise back up to the melting point on a cooling curve.

32. Can you collect soluble gases over water?
0.10M HCl (more ions)
NH4?
bright yellow
No - NH3 and HCl gases are extremely soluble

33. Does Kw increase or decrease with T? Why?
How grouped results are
Increase - the dissociation of water is endothermic so increasing T favors forward direction - thus more ions.
Salt + water.
bases

34. acetates
proton acceptor.
Soluble
bright yellow
yellow

35. What is the sign of the cathode in voltaic cells? in electrolytic cells?
same KE - but PEice<PEwater
neutralization: high K - H2O product dissociation: low K - H2O reactant
same KE - but PEice<PEwater
voltaic: + electrolytic: -

36. halides
K2
Insoluble except for nitrate and acetate
Salt + water
Most are soluble except Ag - Pb

37. When can supercooling occur? What does it look like on a cooling curve?

38. How are metal oxides and hydrides bonded? are they acidic or basic?
allow for the vapor pressure of water and make sure to level levels
metal oxides and hydrides are ionically bonded and basic
Concentration
Decant

39. What is the formula for percent yield?
chemically (ex: with carbon)
Tetrahedral
Experimental mass/theoretical mass X 100
do not change

40. Generally - which oxy acid is strongest?
The one with most oxygen atoms (highest oxidation number)
No - NH3 and HCl gases are extremely soluble
voltaic: + electrolytic: -
Soluble

41. When driving off water from a hydrate - how do you tell you're done?
S2O3²?
HNO3 - (nitric) H2SO4 -(sulfuric) HCl -(hydrochloric) HBr -(hydrobromic) HI - (hydroiodic) HClO4 (perchloric)
Heat to constant mass-weigh - reheat - cool - and weigh again until mass is constant
Soluble

42. What variables effect the moles of substance liberated in electrolysis. (a.k.a. Faraday's Laws)
OH- and NH3
K2
Current - time and charge on ion (moles of e used in half cell reaction)
Potassium permanganate and potassium dichromate (they're clues that a reaction will be redox)

43. ammonium/ammonium compounds
Soluble
+4-covalent - +2-ionic
E=q + w (negative is by system - positive is on system)
Two forms of the same element (same Z) with different # of neutrons and similar chemical properties

44. group 1 ions/compounds
Soluble
How grouped results are
H2O + CO2 (it decomposes readily)
Pale purple - (orange)-yellow - red - blue - green.

45. What are amphoteric oxides?
1) Add together a weak base with a salt of that base made with a strong acid. (or visa versa) 2) by partially neutralizing a weak base with a strong acid or weak acid with a strong base. (Ex: 0.2 mol NH3 + 0.1 mol HCl)
Heat a test tube at an angle at the side of the tube (not bottom)
Oxides that react with both acids (make salts + water) AND bases (forms complex ion - ex: ZnO and Al2O3 in bases make Zn(OH)4²? and Al(OH)4? or Al(OH)6³?)
CnH2n-2

46. How can metals like iron and zinc be reduced?
catalyst=conc H2SO4
Cu3(PO4)2
chemically (ex: with carbon)
Concentration

47. How do you find the pH for a dibasic acid? (H2A)?
Anode - oxygen. Cathode - hydrogen
Perform ICE BOX calculation based on K1
C4H10
Ignore 'x' if its K is very small compared to [reactant] (5% rule)

48. A Bronsted-Lowry base is...
Whether or not they can form H-bonds with water (ex: Ethyl alcohol is soluble but dimethyl ether is not)
proton acceptor.
CN?
CnH2n+1 often designated 'R' ex C3H7 is propyl

49. What electrons are lost/gained first in transition element ions?
Read the bottom of the meniscus
CnH2n-2
Initiation energy (NOT Ea)
ns² electrons (first in-first out)

50. What device would you use to measure a volume of gas?
Eudiometer
Increase - the dissociation of water is endothermic so increasing T favors forward direction - thus more ions.
Reverse most negative E° and add voltages to get Ecell (or take absolute difference between Ered values)
Most INsoluble except group 1 and ammonium