## Glossary of Chem Lab Final 2

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- what does specific heat do?
- identifies an unknown material

- what is a calorimeter?
- insulated container that prevents heat exchange from the process occuring inside the countainer and around it outside.

- heat change of a substance (q)=
- M x C x Change in T

- what is c (specific heat) for water?
- 4.18 j/(g)(degrees c)

- to record a thermogram, what do you press after main menu?
- F2 - Temperature

F1 - Temperature vs. Time

- what is y min and max for determining the calorimeter constant for a styrofoam cup calorimeter?
- 15-75

- what is the equation for deteriming the calorimeter constant for the calorimeter?
- [mass of warm water x C x change in temp of warm water] - [mass of room temp water x C x change in temp of water]

- density = ?
- mass / volume

- equation for finding the volume of a...

cube:

rectangle solid:

sphere:

cylinder: - cube: L3

rectangle solid: L x W x H

sphere: 4/3(3.14)(r3)

cylinder: (3.14)(r2)(L)

- how do you determine the density of an irregularly shaped object?
- use the displacement of water or some other liquid

- does lower specific heat mean the object absorbs heat more slowly of quickly?
- slowly

- what is the equation for determining the specific heat of an unknown metal given the calorimeter constant?
- [mass of room temp water x C x change in temp of water] + [calorimeter constant x change in temp of water] / [mass of solid x change in temp of solid]

- how do you identify an unknown metal nitrate solution via titration with NaOH
- 1. obtain 20 mL of unknown.

2. pipet 10 mL into a 250 mL

beaker and add about 90 mL

water.

3. fill cleaned pipet with 50

mL NaOH.

- how do you preform titrataion using the measurenet workstation?
- F3 - pH/mV

F2 - pH/volume

calibrate

F1

Display

- when done using measurenent, how do you save files?
- file options

F3

enter 3 digit code

Enter

- molarity = ?
- mols / L

- molar ratio = ?
- mol NaOH / mol metal soln

- how do you distinguish an unknown metal nitrate solution via precipitation with NaOH?
- molar ratio

- how do you prepare the five standard solutions from the one concentrated standard soltuion when determining the concentration of an unknown metal solution by absorbance spectrascopy?
- (m1)(v1)=(m2)(v2)

solving for v1

- on measurenet, how do you preform absorbance spectrascopy?
- F5 spectroscopy

F2 absorbance

- for absorbance spectrascopy, what does y = and what is your min/max?
- y = absorbance

max = 2

min = 0

- for absorbance spectrascopy, what does x = and what is your min/max?
- x = wavelength

min and max = leave how it is.

- for absorbance spectrascopy, what is your blank solution?
- water

- for absorbance spectrascopy, what is used to zero? to reference?
- zero = black block

reference = water

- volume should be reported to the what mL?
- 0.001

- will a higher or lower specific heat attain a higher equilibrium (final temperature)
- higher

- how do you find lamba max when preforming absorbance spectrascopy?
- look at the three beer lambert plots given. it will be the peak that is around 1 or less for absorbance. use the highest peak that's the best (least blurry)

- how do you find the absorbance needed when preforming absorbance spectrascopy?
- plug absorbance reading at lamda max intot equaiton for line (given), solving for x.

- how do you determine whether an unknown compound is ionic, polar covalent or nonpolar covalent?
- ionic: use LE light. if it lights up, it's ionic.

polar: will dissolve in water (and not hexane)

nonpolar: will dissolve in hexane (and not water)

- when you standardize an unknown acid via titration, what goes in the buret?
- the acid

- how do you determine the concentration of the unknown acid (or base)?
- take grams of standaard

divide by molar mass

multiply by mol-to-mol ratio (2 humps=2 to 1 ratio, 1 hump=1 to 1 ratio)

then divide by equivilance point (in L)

- how do you find the quivilance point?
- what you start with - wht you finish with

- when standardizingn an unknown base via titration, what goes in the buret?
- the base

- when determining the % mass in an unknown compound in a mixture via titration, what goes in the buret?
- the unknown compound

- how do you find the % mass in an unknown compound in a mixture via titration?
- equivalence point (in L)

multiply by molarity (given)

now you have moles.

multiply moles by molecular weigth (should be given)

divide teh weight that you started with

multiply by 100%