chem lab procedures etc

studied byStudied by 0 people
0.0(0)
learn
LearnA personalized and smart learning plan
exam
Practice TestTake a test on your terms and definitions
spaced repetition
Spaced RepetitionScientifically backed study method
heart puzzle
Matching GameHow quick can you match all your cards?
flashcards
FlashcardsStudy terms and definitions

1 / 39

encourage image

There's no tags or description

Looks like no one added any tags here yet for you.

40 Terms

1
Experiment 1: Measurements I: Density of a Liquid Purpose
Practice measuring devices such as balances, graduated cylinders, and volumetric pipette and determine density of a liquid
New cards
2
Exp 1: Density Formula
Density = Mass/ Volume
New cards
3
Exp 1: How many places is a buret read to?
2 decimal places
New cards
4
Exp 1: If your pipet was calibrated incorrectly so that it transferred 5% too much solution, how would it affect the liquid's density?
If the pipet transferred too much solution into a flask, it would add to the mass. Therefore, it would make the numerator (D=M/V) larger and make the density larger.
New cards
5
Exp 1: Which measured best?
Graduated cylidner gave best results,
New cards
6
Experiment 2: Emission of Light from Hydrogen and Metal Atoms Purpose
The purpose of this lab is to examine the emission spectrum of Hydrogen and identify unknown metal ions using a flame test
New cards
7
Exp 2: How does a spectroscope work?
Light is emitted from a discharge tube and refracted into each color. Each line in spectrum is light of a particular wavelength. Scale readings of spectroscope correspond to known wavelengths and a calibration curve is created.
New cards
8
Exp 2: Why is a calibration curve needed?
Scale on spectroscope is not super accurate
New cards
9
Exp 2: How are frequency and wavelength related?
As frequency increases, wavelength decreases and energy increases. Wavelength and Frequency are inversely related while Energy and Frequency are directly related
New cards
10
Exp 2: Rydberg Equation
n1 is lower energy level, n2 is higher
New cards
11
Exp 2: Rydberg constant?
Rh = 1.097 x 10^7 m^-1
New cards
12
Exp 2: Energy equation
E=hv where h is planck constant
New cards
13
Exp 2: Which series returns to n1=1? And which region of spectrum does this correspond to?

Lyman series. Corresponds to ultraviolet Balmer (n1=2) corresponds to visible Paschen (n1=3) corresponds to infrared

New cards
14
Exp 2: Flame Test?
Heating metal atoms excited the electrons and when they come back down they release a photon which corresponds to some wavelength
New cards
15
How is energy of light and frequency related?
E= hv (planck constant times frequency) meaning it is directly related
New cards
16
Of the following lines in the emission spectrum of helium, which corresponds to the highest energy electron transition?
Lowest wavelength means highest energy transition
New cards
17
EXP 3: Density of a Solid Purpose
The purpose of this lab is to determine the density of a solid through indirect means
New cards
18
Exp 3 procedure
Weigh 25 mL Erlenmyer flask with and without water and divide by density to get volume. Get mass of water surrounding metal by subtracting mass of stoppered flask water metal from mass of empty flask and mass of metal. Divide mass of water by density to get volume. Subtract volumes to get volume of metal. Divide by mass to get density.
New cards
19
One of the lines in the hydrogen atom emission spectrum occurs in the UV region at 397 nm. It results from a transition from an upper energy level to n=2. What is the principle quantum number of the upper energy level?
Solve for higher level (n^2 h)
New cards
20
A graduated cylinder is filled with water to the 25.0 mL mark. After 27.5 g of a solid is added, the volume is 31.5 mL. What is the density of the solid to the proper number of sig figs

31.5 - 25.0 = 6.5 mL 27.5/6.5 = 4.2 g/cm^3

New cards
21
Lab 4: Paper Chromatography Purpose
The purpose of this lab is to create a chromatogram of food dye and to determine unknown ions
New cards
22
Exp 4 Procedure

Add drops of food dye to paper, place in beaker with 1M NaCl and allow it to come up

Do the same thing for part B but with metal ions and NH3

New cards
23
Exp 4: Rf formula

Distance component moved/ Distance solvent moved Can never be greater than 1 since its a ratio

New cards
24
Exp 4: Solvent Front
The solvent front is the distance the solvent moves
New cards
25
Exp 4: Mobile Phase?
The component that interacts most strongly with the mobile (liquid) phase will travel up the paper at a faster rate - thus it will travel the greatest distance in the same amount of time
New cards
26
Exp 5: Using Models to Predict Molecular Structure Purpose
The purpose of this lab is to practice constructing molecules
New cards
27
Exp 5: What is electronegativity
The tendency of an atom to attract electrons
New cards
28
Exp 5: What atoms can possess more than an octet
Elements in the third row and below in the periodic table can form compounds in which they have greater than eight valence electrons. P and Cl are both in the third row.
New cards
29
Exp 5: How to count formal charge?

Formal charge is Valence electrons - bonding electrons (Bonding electrons count as one each, so a single bond counts as one electron, a double bond counts as two)

New cards
30
Exp 5: When is a molecule unstable?
When it breaks the octet rule (and is not allowed to)
New cards
31
Exp 6: Water of Hydration: Purpose
The purpose of this lab was to study the properties of hydrates by identifying them, and determining unknown hydrates
New cards
32
Exp 6: Procedure

Part A: Place crystals of compounds in watch glasses and leave them to see if they pick up or lose water
Part B: Clean crucible and heat it and then weigh. Weigh again with the sample, heat for 10 minutes and then weigh one more time.
Part C: Heat CuSO4 and then add water back into it. Look for physical and color changes
Part D: Heat compound in test tube to see if it is a hydrate

New cards
33
Exp 6: Effloresence vs Hygroscopic vs Deliquescence

Efflorescent substances lose water to air

Hygroscopic substances gain water from humid air

Deliquescent substances take up so much water that they dissolve into water

New cards
34
Exp 6: What defines a true hydrate?

Must release water on heating and be soluble in water

True hydrates are also reversible

New cards
35
Exp 6: How are crystals built
Held together by intermolecular forces like Hydrogen bonding or Dipole-Dipole bonding
New cards
36
Exp 6: How to calculate formula of a hydrate?
First, find the mass of the water. This can be found by subtracting the mass of the crucible, cover, and sample from the mass of the crucible, cover, and anhydrous. Divide this by 18.02 to get your mols of water. Next, find the mass of the anhydrous by subtracting the mass of the empty crucible from the anhydrous. Divide this by the molar mass of the salt. Divide the mols of water by the mols of anhydrous to get n
New cards
37
Exp 6: How do organic carbohydrates behave?
Lose water by being heated but the process is not reversible
New cards
38
Exp 7: Spectrophotometry and Beer's Law: Purpose
The purpose of this lab was to practice using a spectrophotometer and find the mass percentage of Cu in a penny
New cards
39
Exp 7: Procedure

A-

Insert a cuvet of red food dye into spectrometer. Get wavelength being absorbed.

B- Prepare penny solution by combining it with NO3. Find absorbance by placing into spectrometer. Find absorbance vs concentration and make calibration curve.

y=mx+b where absorbance is the y and you solve for x (concentration)

New cards
40
Exp 7: Beer's Law?
Absorbance = molar absorptivity (epsilon) times path length times concentration
New cards

Explore top notes

note Note
studied byStudied by 18 people
60 days ago
5.0(1)
note Note
studied byStudied by 125 people
706 days ago
4.5(4)
note Note
studied byStudied by 15 people
789 days ago
5.0(1)
note Note
studied byStudied by 2 people
67 days ago
5.0(1)
note Note
studied byStudied by 40 people
941 days ago
5.0(3)
note Note
studied byStudied by 12 people
661 days ago
5.0(1)
note Note
studied byStudied by 29 people
963 days ago
5.0(1)
note Note
studied byStudied by 505 people
1 hour ago
4.8(5)

Explore top flashcards

flashcards Flashcard (34)
studied byStudied by 10 people
148 days ago
5.0(1)
flashcards Flashcard (80)
studied byStudied by 5 people
483 days ago
5.0(1)
flashcards Flashcard (124)
studied byStudied by 35 people
427 days ago
5.0(1)
flashcards Flashcard (20)
studied byStudied by 8 people
396 days ago
5.0(1)
flashcards Flashcard (59)
studied byStudied by 11 people
774 days ago
5.0(1)
flashcards Flashcard (37)
studied byStudied by 4 people
767 days ago
5.0(1)
flashcards Flashcard (59)
studied byStudied by 4 people
233 days ago
5.0(1)
flashcards Flashcard (94)
studied byStudied by 85 people
14 days ago
5.0(1)
robot