Chapter 8 Flashcards
It is the science of obtaining processing, and communicating information about the composition and structure of matter
Analytical chemistry
It is a measurement, science consisting of a set of powerful ideas and methods that are useful in all fields of science and engineering
Analytical chemistry
It is the art and science of determining what matter is and how much of the exists
Analytical chemistry
Give at least one definition of analytical chemistry
- The science of obtaining processing and communicating information about the composition and structure of matter
- The art and science of determining what matter is and how much of it exists
- The measurement science consisting of a set of powerful ideas and methods that are useful in all fields of science and engineering
- Suga It requires both qualitative and quantitative information in analysis
What are the roles of analytical chemistry?
It is applied throughout industry, medicine, and all the sciences
Used in laboratories to gather quantitative information
If an analysis more likely reveals the identity of elements and compounds in a sample, what type of analysis is it?
Qualitative analysis
If an analysis more likely indicates the amount of each substance in a sample what analysis is it?
Quantitative analysis
What was the qualitative of a quantitative given example using the metal ions and their emission of light?
Explain the mechanics of this.
Quantitative -> specific wavelength that can be converted into numeric values
Qualitative -> colors that is being emitted when the particle is in certain values
- Ionic solids can produce different colored flames, due to the presence of metal ions in their composition
- When metal ions are heated it can become excited and emit light of specific wavelength
Explain the mechanism of iodine test for starch.
What was the quantitative analysis?
What was the qualitative analysis?
Quantitative -> concentration of the starch
Starch
- carbohydrate molecule found in food like bread
- its molecule is long and coiled
- iodine ends up in the coil which is why it turns from light brown to purple and appears black at high concentration
Qualitative –> color variation that depends on concentrations 1%, 0.1% and 0.01% decreasing 10 times for test tubes.
Describe the characteristics of starch and iodine in iodine test for starch.
Starch
- carbohydrate molecule found in food like bread
- its molecule is long and coiled
- iodine ends up in the coil which is why it turns from light brown to purple and appears black at high concentration
When does the iodine starch test becomes quantitative?
1.) measuring the amount of light that passes through a sample containing the starch iodine complex
2.) Interpreting and converting the amount of light in terms of starch concentration
It is a chemical substance that is the subject of a chemical analysis
Analyte
The result of a typical quantitative analysis are computed from two measurements which are
1.) the mass or the volume of sample to be analyzed
2.) Measurement of some quantity that is proportional to the amount of analyte
How do we classify the analytical method that has been used?
It is classified based on the nature of the final measurement. In example, if the final measurement involves the use of light intensity, the method might be classified as spectrophotometric method.
Depending on what property of the sample is measured in the second step, analytical methods are categorized accordingly. True or false?
True
What are the quantitative analytical methods?
Gravimetric methods
Volumetric methods
Electroanalytical methods
Spectroscopic methods
It is a type of quantitative analytical methods that determine the mass of the analyze or a compound chemically related to it
Gravimetric methods
It is used in gravimetric method when the analyte is precipitated as a solid, which is then filtered, dried and weighed
Precipitation
It this use in gravimetric methods when the analyte is converted into a Volatile compound, which is then vaporize and weighed
Volatilization method
It is a quality of a material which describes how readily a substance vaporizes
Volatility
It is a method that determine the volume of a solution containing a known concentration of a reagent required to react completely with the analyte
Volumetric method
It is a technique in quantitative analysis, specifically volumetric method where a solution of known consideration is used to determine the consideration of an unknown solution
What do we call the known solution?
And what do we call the unknown solution in this reaction?
Titration
Known solution -> titrant
Unknown solution -> analyte
Identify the qualitative analytical method that has been used
A factory needs to monitor the level of pollutants in its wastewater discharge. They collect a sample and want to determine the concentration of sulfate ions present.
By adding a specific reagent, they precipitate sulfate ions as barium sulfate.
After filtration and drying, they weigh the resulting precipitate to determine the concentration of sulfate ions in the wastewater.
Gravimetric method
Identify the qualitative analytical method that has been used
A student is conducting an experiment to determine the concentration of acetic acid in vinegar. They perform a titration with a standardized sodium hydroxide solution. By gradually adding the NaOH solution to the vinegar sample until the reaction is complete, they can determine the concentration of acetic acid present in the vinegar.
Volumetric method
Identify the qualitative analysis method that has been used
A researcher is studying the oxidation-reduction reactions occurring in a fuel cell. They are interested in quantifying the amount of hydrogen gas produced during the reaction. By measuring the electrical current generated by the fuel cell over time, they can calculate the quantity of hydrogen gas produced, providing insight into the efficiency of the fuel cell.
Electronanalytical method
Identify the qualitative analysis method that has been used
A winemaker wants to ensure the quality of their wine by monitoring the concentration of sulfites, which are commonly used as preservatives. They utilize UV-Visible spectroscopy to measure the absorbance of light by the sulfite ions in the wine sample. By correlating the absorbance with known concentrations of sulfites, they can determine the sulfite concentration in the wine.
Spectroscopic method
This analytical method involves the measurement of electrical properties, such as voltage, current, resistance and quantity of electrical charge
Electroanalytical method
These methods of qualitative analysis are based on the interaction between electromagnetic, radiation, and analyte atoms, or molecules, or on the production of such radiation by analytes
Spectroscopic methods
Techniques, such as UV-visible, spectroscopy, infrared spectroscopy, and atomic absorption spectroscopy belong to this category of qualitative analytical method
Spectroscopic method
Techniques like potentiometry, voltammetry, coulometry fall all under the classification of qualitative analytical method
Electroanalytical method
Wavelength of radio in meters
10^3
Wavelength of microwave in meters
10^-2 meters
State the wavelength of
radio
microwave
infrared,
visible,
ultraviolet,
x-ray
gamma ray
10^3
10^-2
10^-5
10^-6
10^-8
10^-10
10^-12
