General chemistry I lab quick reference

Index of Formulas, equations, concepts involved in each lab

Textbook info:

Chemistry, a molecular approach, Nivaldo J Tro, 2nd ed.

Lab 1 Stoichiometry

Textbook:
  • Reaction stoichiometry - 4.2 p140-145
  • Limiting reactant - 4.3 p145-151
  • Balancing equation - p120-123

Lab 2 Measurement

Textbook:

Lab 3 Sig. figure and graphical presentation

Textbook:
  • Sig. figure - p22-25
Concepts and Formulas:

Lab 4 Water of hydration

Textbook:
  • Hydrated ionic compound - p100
  • Reaction stoichiometry - 4.2 p140-145
Concepts and Formulas:

Lab 5 Transformation of Cu

Textbook:
  • Reaction stoichiometry - 4.2 p140-145
  • Limiting reactant and yield - 4.3 p145-151
  • Solution stoichiometry (solution prep.) - 4.4 p152-157
  • Reduction-Oxidation reactions - 4.9 p175-182
  • Balancing equation - p120-123
  • Balancing redox equation - 18.2 p862-865
Concepts and Formulas:

Lab 6 Chemical reactions in microscale

Textbook:
  • Name of ionic compound - 3.5 p97-99
  • Solubility - 4.5 p160-162
  • Molecular, ionic and complete ionic equations - 4.7 p166-168

Concepts and Formulas:

Lab 7 Determination of purity of acid in unknown sample

Textbook:
  • Acid-base titration - 16.4 p769-783
    • Indicators - p780-783
Concepts and Formulas:

Lab 8 Gas law

Textbook:
  • Simple Gas laws (Boyle's, Charles's, Avogadro's) - 5.3 p199-206
  • Ideal gas law - 5.4 p206-209
  • Converting between pressure units - p197 or the second last page of the book
Concepts and Formulas:

Lab 9 Reactivity of metal with HCl

Textbook:
  • Predict whether a metal will dissolve in acid - p877
  • Standard electrode potentials - p873
  • Ideal gas law - 5.4 p206-209
Concepts and Formulas:

Lab 10 Heat of solution and vaporization of nitrogen

Textbook:
  • Heat of solution - p553-555
  • Heat capacity - 6.4 p256-258
  • Thermal energy transfer - p258-260
  • Heat of vaporization - p501-502
  • Hess's law - p271-273
Concepts and Formulas:

Lab 11 Atomic spectroscopy

Textbook:
  • Atomic spectroscopy - 7.3 p306-309, p318-321
  • Electromagnetic spectrum - p299-301
  • Quantum number - p315-318
Concepts and Formulas:

Lab 12 Molecular modeling

Textbook:
  • Orbital filling order - p341
  • Electron configurations, valence electrons - 8.4 p345
  • VSEPR theory - 10.2 p426, 10.3 p430, 10.4 p435
  • VSEPR shape chart - p434
  • Hybridization - p445

Make up lab paper chromatography

Textbook:

Concepts and Formulas:

Concepts and Formulas:

Accuracy and Precision:

Accuracy in measurement system is a degree of closeness of measurements of a quantity to that quantity's actual value. Accuracy is usually measure by percent error.
Precision in measurement system is also known as repeatability or reproducibility. It is the degree to which a series of measurements are close to one another. Precision is usually measured by standard deviation, average deviation and relative standard deviation.

Standard Deviation:

$$ S = \sqrt { \frac { \sum_{ i=1 }^{ n }{ ({ x }_{ i }-\bar { x } )^{ 2 } } }{ n-1 }} $$

legend:

S Standard deviation
sum
xi the ith measurement
\(\bar{x}\) average of measurements
n amount of measurements

Relative Standard Deviation (RSD):

$$ RSD = \frac{S}{\bar{x}}\times 1000 \quad ppt $$ $$ \%-RSD = \frac{S}{\bar{x}}\times 100 \quad \% $$

legend:

S Standard deviation
RSD Relative standard deviation
%-RSD Relative standard deviation in percentage
\(\bar{x}\) average of measurements

Deviation, Average Deviation:

$$ Deviation=\left|x_{i}-\bar{x}\right| \\ AverageDeviation=\frac { \sum _{ i=1 }^{ n }{ \left| { x }_{ i }-\bar { x } \right| } }{ n } $$

legend:

sum
|value| absolute value
xi the ith measurement
\(\bar{x}\) average of measurements
n amount of measurements

unit:

same as measurement

sample calculation:

Trial 1 2 3
weight (g) 2.315 2.321 2.294
avg weight = (2.315 + 2.321 + 2.294) / 3
= 2.310 g
Deviation 1 = |2.315-2.310| = 0.005
Avg. Dev. = ± (|2.315-2.310| + |2.321-2.310| + |2.294-2.310|) / 3
= ± (0.005 + 0.011 + 0.016) / 3
= ± 0.032 / 3
= ± 0.011 g

Ball Volume:

$$ V= \frac {4}{3} \pi {r}^{3} $$

legend:

V Volume
π pi 3.14359
r radius

unit:

cubic length unit (i.e. m3)

Molarity:

$$ Molarity = \frac {{Moles}_{solute}}{{Volume}_{solution}} $$

legend:

Molessolute Moles of solute
Volumesolution Volume of solution

unit:

mol/L

Moles:

$$ Moles = \frac {Weight}{Molecular Weight} \\ Weight = Moles \times Molecular Weight $$

Percent Change:

$$ PercentChange = \frac {\left| Old Value- New Value \right|} {Old Value} \times 100 $$

legend:

|value|: absolute value

sample calculation:

old value new value
3.514 g 4.682 g
percent change = |4.682 - 3.514| / 3.514 * 100
= 1.168 / 3.514 * 100
= 33.24

Percent Error:

$$ PercentError = \frac {\left| Exp. Value - Theoretical Value \right|} {Theoretical Value} \times 100 $$

legend:

|value|: absolute value

sample calculation:

Theoretical. value Exp. value
3.514 g 4.682 g
percent change = |4.682 - 3.514| / 3.514 * 100
= 1.168 / 3.514 * 100
= 33.24

% Yield:

$$ Percent Yield = \frac {{Amount}_{exp}} {{Amount}_{theoretical}} \times 100 $$

legend:

Amountexp Experimental amount
Amounttheoretical Theoretical amount
Amount Mass or moles

unit:

percent %

sample calculation:

Amountexp 0.45 g
Amounttheoretical 1.21 g
% yield = 0.45 / 1.21 * 100
= 37 %

Retention Factor:

$$ Retention Factor ({R}_{f}) = \frac {{Distance}_{spot}}{{Distance}_{solvent}} $$

legend:

Distancespot Distance traveled by spot
Distancesolvent Distance traveled by solvent

unit:

unitless

sample calculation:

Distancespot 78.0mm
Distancesolvent 100.0mm
Retention factor = 78.0 / 100.0
= 0.780

Gas laws:

Ideal gas law:

$$ PV=nRT $$

legend:

P Pressure (Pa, torr, atm)
V Volume
n Moles
R Ideal gas constant, 0.08206 L·atm/(mol·K)
T Temperature (kelvin)
sample calculation:
  • Calculate n from following data:
P 724.54 torr
V 354.4 mL
T 21.2 oC

$$ n = \frac {PV}{RT}=\frac {724.54torr \frac {1atm}{760torr} 354.4ml \frac {1L}{1000ml}} {0.08206 \frac {L \cdot atm}{mol \cdot K}(21.2 + 273.15)K}=0.01399mol $$


Boyle's law:

$$ P\quad \propto \quad \frac { 1 }{ V } \\ P \cdot V\quad =\quad k $$

legend:

P Pressure
V Volume
\(\propto \) proportional to
k Constant (sealed system at constant temperature)

Gay-Lussac's law:

$$ P\quad \propto \quad T \\ \frac {P}{T} \quad =\quad k $$

legend:

P Pressure
T Temperature
\(\propto \) proportional to
k Constant (sealed system with constant volume)

Thermal energy transfer:

For a isolated system with only your system and its surrounding environment:

$$ {q}_{sys}=-{q}_{surrounding} $$

legend:

qsys heat absorbed by system (negative if heat given out)
qsurrounding heat absorbed by environment (negative if heat given out)

Heat capacity and temperature change:

$$ q\quad =\quad m\times { C }_{ s }\times \Delta T \\ \Delta T\quad =\quad { T }_{ f }-{ T }_{ i } $$

legend:

q Heat transfered
m Mass
Cs Specific heat capacity
ΔT Temperature change
Tf Final temperature
Ti Initial temperature

Heat of solution:

$$ \Delta { H }_{ solution }\quad =\quad \frac { { q }_{ solution } }{ n } $$

legend:

ΔHsolution Heat of solution
qsolution Amount of heat required in dissolution of substance in water
n Moles of dissolved substance

Heat of vaporization:

$$ \Delta { H }_{ vapor }\quad =\quad \frac { { q }_{ vapor } }{ m } \\ molar\quad \Delta { H }_{ vapor }\quad =\quad \frac { { q }_{ vapor } }{ n } $$

legend:

ΔHvapor Heat of vaporization
qvapor Amount of heat required in vaporization
m Mass of vaporized substance
n Moles of vaporized substance

Emission spectrum of hydrogen:

$$ \frac { 1 }{ \lambda } \quad =\quad \frac { { R }_{ H } }{ hc } \left( \frac { 1 }{ { { n }_{ f }^{ 2 } } } -\frac { 1 }{ { n }_{ i }^{ 2 } } \right) $$

legend:

λ Wave length
RH Constant: 2.179 × 10-18 J
h Planck constant: 6.626 × 10-34 J·s
c Speed of light in vacuum: 2.998 × 108 m/s
nf Principal quantum number of the final energy level
ni Principal quantum number of the initial energy level