CHEM 212 LAB REPORT 3 2023/2024| PORTAGE
LEARNING|WITH PROCEDURES, EXPLANATION
AND FINAL RESULTS.HIGHLY VERIFIED
Experiment #: Lab 3 Title: Enzymatic Activity of
Lactase
homogeneous sample - ANSWER A sample with a consistent composition
throughout.
(ex. Solid chocolate bar)
Heterogeneous sample - ANSWER A sample with differing compositions throughout.
(ex. peanut and caramel chocolate bar)
sample preparation - ANSWER transforming a sample into a state that is suitable for
analysis
Analyte - ANSWER A substance that is being identified or measured in a laboratory
test.
Quantitative transfer - ANSWER Moving a solution from one vessel to another
without losing any analyte in the process.
composite sample - ANSWER A representative sample prepared from a
heterogeneous material. If the material consists of distinct regions, the composite is
made of portions of each region, with relative amounts proportional to the size of
each region.
calibration curve - ANSWER a graph of detector response as a function of analyte
concentration
standard solution - ANSWER a solution of known concentration
General steps in a chemical analysis - ANSWER 1. Formulating the question
2. Selecting analytical procedures
3. Sampling
4. Sample preparation
5. Analysis
6. Reporting and interpretation
7. Drawing conclusions
aliquot - ANSWER A portion of a well-mixed sample removed for testing
random heterogeneous material - ANSWER A material in which there are fine-scale
differences in composition with no pattern or predictability. When you collect a
, portion of the material for analysis, you obtain some of each of the different
compositions.
random sample - ANSWER a sample in which every element in the population has
an equal chance of being selected
segregated heterogeneous material - ANSWER A material in which differences in
composition are on a large scale. Different regions have obviously different
composition. (ie a section of forest or a lake)
Acuracy - ANSWER how close a measured value is to an accepted value
Precision - ANSWER a measure of how close a series of measurements are to one
another
Sensitivity - ANSWER the capability of responding reliably and measurably to
changes in analyte concentration.
Interference - ANSWER occurs when a species other than analyte increases or
decreases the response of the analytical method and makes it appear that there is
more or less analyte than is actually present.
Masking - ANSWER When the presence of an interfering species prevents the
detection of the analyte.
representative sample - ANSWER a sample that accurately reflects the
characteristics of the population as a whole
Concentration - ANSWER A measurement of how much solute exists within a certain
volume of solvent
Molarity - ANSWER the number of moles of solute per liter of solution
Density - ANSWER Mass per unit volume
(g/L)
weight percent (wt%) - ANSWER mass of solute/mass of solution x 100
ppm (parts per million) - ANSWER 1 gram of solute per 1 million grams of total
solution
ppb (parts per billion) - ANSWER 1 gram of solute per 1 billion grams of total solution
weight percent - ANSWER mass of one component divided by the total mass of the
mixture, multiplied by 100%
volume percent - ANSWER volume of solute/volume of solution x 100
Solute - ANSWER A substance that is dissolved in a solution.
LEARNING|WITH PROCEDURES, EXPLANATION
AND FINAL RESULTS.HIGHLY VERIFIED
Experiment #: Lab 3 Title: Enzymatic Activity of
Lactase
homogeneous sample - ANSWER A sample with a consistent composition
throughout.
(ex. Solid chocolate bar)
Heterogeneous sample - ANSWER A sample with differing compositions throughout.
(ex. peanut and caramel chocolate bar)
sample preparation - ANSWER transforming a sample into a state that is suitable for
analysis
Analyte - ANSWER A substance that is being identified or measured in a laboratory
test.
Quantitative transfer - ANSWER Moving a solution from one vessel to another
without losing any analyte in the process.
composite sample - ANSWER A representative sample prepared from a
heterogeneous material. If the material consists of distinct regions, the composite is
made of portions of each region, with relative amounts proportional to the size of
each region.
calibration curve - ANSWER a graph of detector response as a function of analyte
concentration
standard solution - ANSWER a solution of known concentration
General steps in a chemical analysis - ANSWER 1. Formulating the question
2. Selecting analytical procedures
3. Sampling
4. Sample preparation
5. Analysis
6. Reporting and interpretation
7. Drawing conclusions
aliquot - ANSWER A portion of a well-mixed sample removed for testing
random heterogeneous material - ANSWER A material in which there are fine-scale
differences in composition with no pattern or predictability. When you collect a
, portion of the material for analysis, you obtain some of each of the different
compositions.
random sample - ANSWER a sample in which every element in the population has
an equal chance of being selected
segregated heterogeneous material - ANSWER A material in which differences in
composition are on a large scale. Different regions have obviously different
composition. (ie a section of forest or a lake)
Acuracy - ANSWER how close a measured value is to an accepted value
Precision - ANSWER a measure of how close a series of measurements are to one
another
Sensitivity - ANSWER the capability of responding reliably and measurably to
changes in analyte concentration.
Interference - ANSWER occurs when a species other than analyte increases or
decreases the response of the analytical method and makes it appear that there is
more or less analyte than is actually present.
Masking - ANSWER When the presence of an interfering species prevents the
detection of the analyte.
representative sample - ANSWER a sample that accurately reflects the
characteristics of the population as a whole
Concentration - ANSWER A measurement of how much solute exists within a certain
volume of solvent
Molarity - ANSWER the number of moles of solute per liter of solution
Density - ANSWER Mass per unit volume
(g/L)
weight percent (wt%) - ANSWER mass of solute/mass of solution x 100
ppm (parts per million) - ANSWER 1 gram of solute per 1 million grams of total
solution
ppb (parts per billion) - ANSWER 1 gram of solute per 1 billion grams of total solution
weight percent - ANSWER mass of one component divided by the total mass of the
mixture, multiplied by 100%
volume percent - ANSWER volume of solute/volume of solution x 100
Solute - ANSWER A substance that is dissolved in a solution.
