54 terms

H Chemistry Chapters 1 and 3

the scientific method
1. make observations
2. test hypotheses (Identify controls)
3. develop theories (analyze)
4. scientific laws (abstract)
numeric problem solving steps
1. analyze (know and find list)
2. calculate
3. evaluate (check answer)
organic chemistry
the study of all chemicals containing carbon
inorganic chemistry
the study of all chemicals not containing carbon
the study of processes that take place within living organisms
analytical chemistry
study of the composition of matter
physical chemistry
study of energy transfer when a chemical undergoes change
pure chemistry
pursuit of chemical knowledge for its own sake with no immediate practical use
applied chemistry
research directed toward a practical goal or application
kinetic theory
particles in matter are in constant motion
What do changes in free energy enable?
They allow one to predict whether a reaction will actually occur under a given condition.
carbon chemistry
new carbon compounds are created every day (making synthetic materials)
prediction of the experiment
independent variable
stays the same
dependent variable
things that effect the results of the experiments
co-dependent variables
other dependent variables that effect the experiement
number of experiments
1 is enough for chemistry
to what extent is your data overgeneralized or limited?
control experiments
every detail and possibility of effecting change in chemicals is addressed
experimental controls
trying to figure out what to test by eliminating other parts of the procedures that effect the experiment
blind experiment
the person being experimented on doesn't know what the effect is - influences on experiment with placebo effect
double blind experiment
neither the person being experimented on nor the person conducting the experiment know the effect of the experiment
example of a double blind experiment
MSG reactions
raw data is
collected from the experiment
processed data is
how you process the raw data - interpretations (BIAS)
what are the possibilities of conclusions of an experiment?
1. data supports hypothesis
-is it supported well enough statistically?
2. data doesn't support hypothesis
-what needs to be changed? the hypothesis? do more experiments? modify the experiement?
3. data does not support or disprove hypothesis
upon completing an experiment, what should you ask yourself?
How do you need to modify your experiment?
procedural errors
how are you doing the experiment? what are the material controls?
equipment errors
incorrect measuring? error in technology?
human factor
incorrect procedure following?
how close to the theoretical answer something is.
-how close of units measured
-do you know what the theoretical amount is supposed to be?
how consistent measurements are.
With accuracy and precision, which is the affector of which?
precision effects accuracy
Why is there greater error with a measuring tool with a wider tube?
A wider tube enables a greater curve of the meniscus therefore skewing your measurements.
Sigdigs are the
reflection of the accuracy of your numbers/measurements
With metric unit conversions, convert
the smaller unit to the larger unit
With metric unit conversions, add the numerical change to
the base unit - keep the unit with the prefix without a coefficient
a quantity that has both a number and a unit
how do you multiply 2 numbers in scinot?
multiply the coefficients and add the exponents
how do you divide 2 numbers in scinot?
divide the coefficients and subtract the divisor exponent from the dividend exponent
how do you add/subtract 2 numbers in scinot?
convert to the same exponent, then add or subtract the coefficients
accepted value
the correct value for the measurement based on reliable references (the accurate value)
experimental value
the value measured in the lab (the precise value)
how do you determine error?
experimental value - accepted value = error
how do you calculate the percentage of error?
error / accepted value * 100% = percent error
instruments that differ in the number of sigfigs that can be obbtained from their use differ
in the precision of measurements
a calculated answer expressed in sigfigs
cannot be more precise than the least precise measurement from which it was calculated
How are the following quantities expressed metrically (these are the 7 vase units)?:
1. length
2. mass
3. temperature
4. time
5. amount of substance
6. luminous intensity
7. electric current
1. meter (m)
2. kilogram (kg)
3. Kelvin (K)
4. second (s)
5. moles (mol)
6. candela (cd)
7. amphere (A)
energy and how it is measured
the capacity to do work or produce heat measured in Joules (J) or calories (cal)
temperature measurements
*absolute zero
an object's temperature determines
the direction of heat transfer
(heat moves from the hotter object to the colder object)
temperature is determined by
energy and the motion of particles
the ratio of the mass of an object to its volume
density vs. temperature
density and temperature are inverse qualities (mass however always stays the same)