Periodic Trends
Hybridization
Reaction Energetics
Net-Acid Base Reactions
Mystery
100
Rank the following elements in order of increasing electronegativity:
Sulfur, Oxygen, Neon, Aluminum
Ne, Al, S, O
100
How many sigma and pi bonds are in the molecule below?
3 sigma, 1 pi
100
What is the sign of ΔH and ΔS when moving along the green arrow?
ΔH > 0; ΔS > 0
100
Which species is/are the best lewis acid?
A, c, e
100
The combustion of ethanol is given by the equation C2H5OH + 3O2 → 2CO2 + 3H2O. How many moles of carbon dioxide will be produced in the burning of 3.77 moles of ethanol?
7.54 mol
200
Order the following elements in order of atomic radius:
Xenon, Fluorine, Rubidium, Tin, Strontium
F, Xe, Sn, Sr, Rb
200
What are the hybridization and molecular geometry around atom 1 in the lewis structure below?
Sp2; trigonal planar
200
For some systems: 180 J of work is done on a system and while it gives off 340 J of heat. What are ΔEsys, ΔEsur and ΔEuniv?
ΔEsys = -160 J
ΔEsur = 160 J
ΔEuniv= 0 J
200
What is the conjugate acid for the following base:
H2PO4-
H3PO4
200
In the following chemical reaction, which is the oxidizing agent and which is the reducing agent?
Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l)
Ox: HNO3(aq)
Red: Cu(s)
300
Is it easier to form a positive ion with an element that has high ionization energy or an element that has low ionization energy? Why?
Low, since ionization energy is the energy required to remove an electron, it is easier to form a cation (lose an electron) with a lower ionization energy
300
Which indicated bond(s) is/are the longest?
A
300
Use the Table of Bond Energies to estimate the enthalpy change in each of the following reaction:
CH2Br2(g) + F2(g) → CH2F2(g) + Br2(g)
-452 J
300
Determine the type of arrows that should be used for the following reaction given the Ka if each acid:
Ka(HClO) = 3.5x10-8
Ka(HCN) = 4.0x10-10
HCN + ClO1- [ ? ] CN1- + HClO
Double arrows
300
Is the following process spontaneous? What is the sign of ΔG?
A + B2- → A2- + B
No; ΔG > 0
400
Put the following elements in order from lowest to highest first ionization energy:
Aluminum, Argon, Cesium, Sodium
Cesium, Sodium, Aluminium, Argon
400
Which orbital set would form a pi antibonding orbital?
D
400
What is the sign of ΔH, ΔS, and ΔG when cooling methane from -185.7 degrees C to -191.2 degrees C when the freezing point of methane is -182°C and the boiling point of methane is -161.5°C?
ΔH < 0
ΔS < 0
ΔG < 0
400
Write the net acid-base reaction for the following reaction (don’t forget your arrows):
NaC2H3O2 + H3PO4 → ?
H3PO4 + C2H3O2- ⇌ H2PO4- + HC2H3O2
400
What is the oxidation number of chromium in calcium dichromate (CaCr2O7)?
+6
500
Which group tends to form +2 ions?
Group 2 alkaline earth metals
500
Given a MO diagram with 5 molecular orbitals (shown below), indicate where, if any, nodal planes would be formed and determine the interaction at each nodal plane (bonding, antibonding, nonbonding).
B, d, f, h; antibonding
500
Indicate the sign of entropy change for the following reaction (large positive, large negative, or nearly zero):
N2H4(g) → N2(g) + 2H2(g)
Large positive
500
Write the net acid-base reaction for the following reaction:
HF + NaCN → ?
HF + CN- → F- + HCN
500
The reaction occurring at the cathode of one primary cell is
2MnO2(s) + H2O(l) + 2e- → Mn2O3(s) + 2OH−(aq)
During this reaction, the oxidation state of the manganese is changing from…..
The manganese is changing from +4 to +3. A decrease in oxidation number shows that the manganese is being reduced.