Qual and Quan Flashcards
What are the two types of chemists
Synthetic and Analytical
What does a synthetic chemist do
make new and improved materials
What does a Analytical chemist do
test and analyze materials and the materials’ properties
What types of analysis do Analytical chemists perform
Quantitative and Qualitative analysis
What is a quantitative analysis
determines the amount of something in a substance
what is a qualitative analysis
identify the substance (figure out which element and/or compound is present )
What are the three ways to determine the presence of a species in qualitative observation
- indicators
- precipitation rxns
- solution color changes
what was the chemical equation for the center well in “Acid rain in a bag”
copper+nitric acid-> copper nitrate+ nitrogen dioxide gas+ water
What were the middle wells filled with in “Acid Rain in a bag”
Distilled Water
What gas was produced that dissolves in water in “Acid rain in a bag”
NO2 gas
nitrogen dioxide
What does the dissolving of the NO2 gas in water produce in the “Acid Rain in a bag” lab
Acid Rain
What were the outer wells filled with in “Acid rain in a bag”
Universal indicator solution
What happens when the colors change in “acid rain in a bag”
the pH falls
What are the two types of water pollution
Point and Nonpoint Specific Pollution
What is point specific pollution
- comes from a specific area
- easily solved
- ex: factory with discharge pipe in water
What is non point specific pollution
- comes from not just one location
- ex: runoff water
In “Chemical Analysis of water” where does the polluting ion carbonate come from
Rocks like limestone & dissolved atmospheric CO2
In “Chemical Analysis of water” where does the polluting ion chloride come from
Rocks and soil
In “Chemical Analysis of water” where does the polluting ion sulfate come from
Rocks and soil
In “Chemical Analysis of water” where does the polluting ion Lead (II) come from
Gasoline additive
In “Chemical Analysis of water” where does the polluting ion Phosphate come from
Fertilizers, detergent, waste (excrements)
In “Chemical Analysis of water” where does the polluting ion Iron (III) come from
Rocks and soil Industrial waste (corroding pipes)
In “Chemical Analysis of water” where does the polluting ion Chromate come from
Industrial waste (paint)
In “chemical analysis of water” _____ was added to carbonate which resulted in __________
- hydrogen
2. bubbles
In “chemical analysis of water” _____ was added to chloride which resulted in __________
- silver
2. white solid
In “chemical analysis of water” ____was added to sulfate which resulted in __________
- barium
2. cloudy white milky
In “chemical analysis of water” _____ was added to Chromate which resulted in __________
- hydrogen
2. dark blue
In “chemical analysis of water” _____ was added to iron (III) which resulted in __________
- thiocyannate
2. blood red
In “chemical analysis of water” _____ was added to Lead (II) which resulted in __________
- chromate
2. bright yellow solid
In “chemical analysis of water” _____ was added to phosphate which resulted in __________
- silver
2. pale yellow
In “Chemical Analysis of water” which ion solution was contaminated so was not performed
Phosphate ion
What testing was used in “Lead in soil” lab
Rhodizonate testing
“Lead in soil” Yellow colored sodium rhodizonate reacts with ___ to form a pink complex
lead
What were limitations to the method used in “Lead in soil
- Other metals (tin, silver, cadmium, and barium) form pink complex too
- The test solution degrades quickly (test kits must be used within minutes of mixing)
What method was used in the “Lead in Soil” lab
colormetric
What are the three types of quantitative analysis
- Volumetric
- Gravimetric
- Instrumental
What is Volumetric analysis and what technique is used in it
measure volume of a substance with a known concentration to calculate the MASS of an unknown
Technique used – titration
what is gravimetric analysis
measure the mass of a precipitate formed and use atomic mass to calculate MASS of unknown in the precipitate
what is the endpoint in volumetric analysis
End point: when all of the unknown substance is used up (reaction stops)
Volumetric analysis Involves the use of ____, which visually shows you reaction completion (the end point).
an indicator
What is the indicator in “Ca in milk”
Hydroxynapthol blue is the indicator
what is EDTA in “Ca in milk”
- is electron donor (like single replacement) so oxidation reduction
- like a claw (surrounds the calcium ion and pulls it inside of itself spherical molecule)
what is the indicator in “Ascetic Acid in vinegar”
Phenolthalein is the indicator (clear in vinegar to pink when reaction complete)
What is vinegar titrated with in “Ascetic acid in vinegar”
Vinegar (unkown) is placed in Erlenmeyer flask and is titrated with NaOH (in buret)
What type of rxn occurs in “Ascetic Acid in vinegar”
acid/base rxn
What is the aimed percent acidity in “Ascetic acid in vinegar”
5%
What rxn is involved in gravimetric analysis and what MUST form
precipitation rxn
1 solid must form
what are the final three steps to achieving your answer in gravimetric analysis
filter
dry
weigh substance
What are industrial uses of gravimetric analysis
- Measurement of the “essential” elements in plant foods (phosphorus, for example, is converted into the insoluble salt, magnesium ammonium phosphate)
- Estimation of pollutants in the air, such as sulfur dioxide (by conversion to insoluble barium sulfate)
- Estimation of sulfur dioxide (used to prevent spoilage) in soft drinks, such as orange juice.
- Estimation of chloride ions in water supplies (by conversion to insoluble silver chloride).
- Water quality studies filter retailers
Vocab: what is an indicator
changes color in response to pH movement and visually shows the experimenter that the reaction has run to completion.
Vocab: What is the end point
the point at which the indicator changes color to visually show when all of the unknown substance has been fully consumed by the reaction (reaction stops)
Vocab: What is titration
the common laboratory technique used in volumetric analysis
Vocab: What is Gravimetric Analysis
uses the solubility rules to pull the ion of interest out of solution as a solid. Then, the mass of the precipitate formed is measured and used to calculate MASS of unknown ion in the precipitate.
Vocab:What is Volumetric Analysis
uses the volume ( mL) of a substance of known concentration (molarity = moles per liter) to calculate the mass of another substance.
Industrial uses of volumetric analysis
- Food Chem- calculate nutritional information (mg of Ca in milk, acidity of vinegar etc)
- Quality Control- pharmecutecals, cleaning products, water treatment plants, cosmetics
Draw the diagram of the ascetic acid in vinegar lab
:)
Equation of molar concentration
moles/liters
In the labs “ca in milk” and “Ascetic acid in vinegar”, the indicator was added to what
solution containing unknown amounts of a substance
What is the known concentration of EDTA
0.04 M
industrial uses qual. analysis
forensic chemists
pharm chemists- impuritues in new substances
enviro. chemists- ion tests in water
