Lab Final

Question 1

Mathematical model for water cooling from experiment 1

Answer 1

Exponential decay

Question 2

Nominal volume

Answer 2

The volume given by the measuring device. May differ from the true volume appreciably.

Question 3

Mean deviation formula

Answer 3

(Σ|x - x̄ |)/n

Question 4

Can pentane solutions be poured down the sink?

Answer 4

No!

Question 5

How do you clean the glassware in experiment three, in which pentane and oleic acid was used?

Answer 5

Rinse the glassware with acetone or pentane, NEVER water!

Question 6

Flow of light through a spectrophotometer

Answer 6

Light source –> lens –> sample cell –> slit –> diffraction grating –> diode array detector

Question 7

Beer’s Law

Answer 7

Relates absorbance to concentration

A = (molar absorptivity)(path length)(concentration)

Question 8

What temperature is a bunsen burner in its dark blue inner cone?

Answer 8

Extremely hot

Question 9

What temperature is a bunsen burner in its pale blue violet outer region?

Answer 9

Moderately hot

Question 10

What temperature is a bunsen burner if its flame is luminous and yellow?

Answer 10

Cool

Question 11

Concentration (c) calculation

Answer 11

= (absorbtivity)(cm or unit of length) / (absorbance) = ab/A

Question 12

Percent yield formula

Answer 12

(Experimental mass / theoretical mass) times 100

Question 13

In the redox reaction involving hydrogen peroxide and permanganate, what is being oxidized?

Answer 13

Oxygen / hydrogen peroxide

Question 14

In the redox reaction involving hydrogen peroxide and permanganate, what is being reduced?

Answer 14

Manganese / permanganate

Question 15

In the redox reaction involving hydrogen peroxide and permanganate, what is the oxidizing agent?

Answer 15

The permanganate ions

Question 16

In the redox reaction involving hydrogen peroxide and permanganate, what is the reducing agent?

Answer 16

The hydrogen peroxide

Question 17

What was the purpose of the NaOH in the first part of the neutralization experiment?

Answer 17

The solution of unknown concentration being titrated

Question 18

What was the purpose of the KHP (potassium hydrogen phthalate) in the first part of the neutralization experiment?

Answer 18

The standard solution of known concentration used as the titrant or reagent for the NaOH solution of unknown concentration

Question 19

What was the purpose of the NaOH in the second part of the neutralization experiment?

Answer 19

The standard solution of known concentration used as the titrant or reagent for the vinegar solution of unknown concentration

Question 20

What was the purpose of the vinegar in the second part of the neutralization experiment?

Answer 20

The solution of unknown concentration being titrated

Question 21

What was the purpose of the phosphoric acid in the third part of the neutralization experiment?

Answer 21

The solution of concentration being titrated to determine how many times the acid has reacted with the titrant

Question 22

What was the purpose of the NaOH in the third part of the neutralization experiment?

Answer 22

The standard solution of known concentration used as the titrant or reagent for the phosphoric acid solution of unknown concentration

Question 23

Hess’s Law is dependent on…

Answer 23

The first law of thermodynamics, which states that energy cannot be created nor destroyed.

It also depends on enthalpy being a state function

Question 24

How to standardize the molarity of a titrant?

Answer 24

Moles of analyte present / original volume of the analyte

Question 25

True volume

Answer 25

The volume etched on the side of the volumetric glassware

Question 26

What kind of powder was used to enhance the visibility of the oil layer in that one useless experiment?

Answer 26

Lycopodium powder

Question 27

Does water density change with temperature?

Answer 27

Yes

Question 28

Which test should be used to determine if an outlying value can be omitted from a data set?

Answer 28

Q Test

Question 29

What transition metal was contained within the compound analyzed via absorption spectroscopy this semester in experiment 4?

Answer 29

Chromium

Question 30

Do all crystalline materials have the exact atom ratios predicted by their molecular formulae?

Answer 30

Nope

Question 31

What is the endpoint of permanganate redox titration?

Answer 31

A pale pink color

Question 32

Which law states that “If two elements combine to form more than one compound, then the amounts of element A that combine with a fixed amount of element B will be in a ratio of small whole numbers?

Answer 32

The Law of Multiple Proportions

Question 33

According to Boyle’s law, as volume (V) decreases, pressure (P) increases. A graph of 1/P on the x-axis and V on the y-axis should…

Answer 33

Be Linear and not regress to zero

Question 34

The molar volume of what two gases were determined in the molar volume of a gas experiment?

Answer 34

Hydrogen and Oxygen

Question 35

A gas that has a pressure of 1.0 atm and volume of 45 mL at 25°C is heated to 78°C. If the pressure remains constant, does the volume increase or decrease?

Answer 35

Increase