Chemistry Mentor Sample Quiz Packet (S2017)
Chemistry Mentor Quiz Topics:
 Lewis Structure, Formal Charge, & Resonance Structures
 Organic Nomenclature and Isomers
 Gas Laws and Stoichiometry
The following are sample questions similar to the quiz problems you might encounter.
The quiz problems might contain multiple topics such as “limiting reagent with
thermochemistry” or “limiting reagent with gas laws”.
Bring a scientific calculator for the quiz; however, the reference table/formula sheet at the end of
this document will be provided.
Please solve the problems in easy-to-understand steps. Make sure to explain the reasoning
behind each step.
Sample Question One – Lewis Structure, Formal Charge, & Resonance Structures:
Assign formal charges to all the atoms in the following Lewis structure of hydrazoic acid HN3.
Suggest a lower-energy resonance structure for the molecule and explain why it is more stable
than the one shown above.
Sample Question Two – Organic Nomenclature:
Write the condensed or bond-line structures of the following compounds.
a)
b)
c)
d)
e)
2,2-dimethyloctane
1,3-dimethylcyclopentane
1,1-diethylcyclohexane
6-ethyl-5-isopropyl-7-methyloct-1-ene
cis-pent-2-ene
Chemistry Mentor Sample Quiz Packet (S2017)
Sample Question Three – Gas Laws:
A sample of an unknown gas with a mass of 3.620 g was made to decompose into 2.172 g of O2
and 1.448 g of S. Before the decomposition, this sample occupied a volume of 1120 mL at 75
cm Hg and 25.0 °C. What is the molecular formula of this gas?
Sample Quiz Solutions
Fall 2017
Sample Question One – Lewis Structure, Formal Charge, & Resonance Structures:
Assign formal charges to all the atoms in the following Lewis structure of hydrazoic acid HN3.
Suggest a lower-energy resonance structure for the molecule and explain why it is more stable
than the one shown above.
Solutions:
The second structure shown few number of formal charges and smaller magnitude of formal
charges. However, the overall charge of the molecule is the same (zero).
Sample Quiz Solutions
Sample Question Two – Organic Nomenclature:
Write the condensed or bond-line structures of the following compounds.
a)
b)
c)
d)
e)
2,2-dimethyloctane
1,3-dimethylcyclopentane
1,1-diethylcyclohexane
6-ethyl-5-isopropyl-7-methyloct-1-ene
cis-pent-2-ene
Solutions:
Fall 2017
Sample Quiz Solutions
Fall 2017
Sample Question Three – Gas Laws:
A sample of an unknown gas with a mass of 3.620 g was made to decompose into 2.172 g of O2
and 1.448 g of S. Before the decomposition, this sample occupied a volume of 1120 mL at 75
cm Hg and 25.0 °C. What is the molecular formula of this gas?
Solutions:
Chemistry I Reference Tables and Formula
Chemistry Mentor Quiz
Spring 2017
R = 8.314 J·mol–1·K–1 or R = 0.08206 L·atm·mol–1·K–1
NA = 6.022 × 1023
1 atm = 760 mmHg = 760 torr = 1.01325 bar = 1.01325 × 105 Pa = 14.7 psi = 29.92 in Hg
 d 
PA = χA PTotal
PV = nRT
dB
effusion rate ( A)


effusion rate ( B)
dA
 1
1
 RH  2  2

n2
 n1
1
E = hν
En = – (2.18 × 10–18J) 1/n2 (Hydrogen Atom)
c = νλ
h
h

p mu
KEelectron = hν – Ф
q = CΔT
h = 6.626 × 10–34 J·s
RH = 1.096776 × 107 m–1
Momentum: p = mu

3RT
M
1 D = 3.34 ×10–30 C • m
c = 2.998 × 108 m/sec




u rms 
2 

 Pmeas  n a (Vmeas  nb)  nRT

V 2 

MB
MA
Boltzmann Constant: kB = R/NA
me = 9.10939 × 10–31kg
PM
RT
KE 
mu 2
p2

2
2m
  q(r )
(note u = velocity,
ν = frequency)
q (electron)  1.6 10 19 C
or if atom or molecule KEelectron = hν – IE (Ionization Energy)
C = heat capacity = m (specific heat)
ΔE = q + w
w = – PΔV
H = ΔE + PΔV
C = heat capacity = m (specific heat) = n Cm
m = sample mass
n = moles of sample
Cm = molar heat capacity

H rxn
  mH f (products)   nH f (reactants)
pH = –log[H+]
Ka × Kb = Kw
pOH = –log[OH–]
Kw = 1.0 × 10
–14
pH + pOH = 14.00
[H  ][A  ]
Ka 
[HA]
(at 25°C)
K p  K c ( RT ) n
Quadratic equation: ax2 + bx + c = 0
x
 b  b 2  4ac
2a
[BH  ][OH  ]
Kb 
[B]