Chemistry exam 15.06-16 Flashcards Preview

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Flashcards in Chemistry exam 15.06-16 Deck (23):
1

Define azeotropes

An azeotrope or a constant boiling mixture is a mixture of two or more liquids whose proportions cannot be altered by simple distillation.

2

2 examples of azeotropes

- Positive: Ethanol
- Negative: Hydrochloric acid

3

Define colligative properties

Properties of solutions that depend on the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the type of chemical species present.

4

2 examples of colligative properties

- Elevation of boiling point
- Depression of freezing point

5

Define the third law of thermodynamics

Regarding the properties of systems in equilibrium at absolute zero temperature:

6

Define Avogadro’s law

Equal volumes of all gases, at the same temperature and pressure, have the same number of molecules

7

Wright Van der Waals equation

(P+(an^2/v^2) (V-nb)=nRT

8

Nernst equation for Zn

lnQ= ln (conc of reduced component/conc of oxidized component)

lnQ= ln(Zn2+/Zn)

9

Define internal energy (equation)

In thermodynamics, the internal energy of a system is the energy contained within the system*
∆U ≝ Q + W

10

Stabilizers of colloids

- electrical charge
- hydration (solvation)
- protective colloids

11

Name a non-ionic surfactant and a cationic surfactant

Non-ionic surfactan:
- fatty alcohols,
- Cetyl alcohol,
- Stearyl alcohol,
- Cetostearyl alcohol
- Oleyl alcohol.

Cationic surfactant:
- Bronidox
- Thonzonium bromide
- Pahutoxin
- Olaflur

12

Define reverse osmosis

Reverse osmosis (RO) is a water purification technology that uses a semipermeable membrane to remove ions, molecules and larger particles from drinking water.

13

Define retention factor is TLC

Rf= distance traveled by the compound/ distance traveled by the solvent front
0 < Rf < 1

14

Which is an example of a thickener?

Xanthan gum,
Gum Arabic,
Gum Tragacanth,
Guar gum,
Locus bean gum,
Gellan gum,
Sodium Alginate,
Carrageenans,
Kappa

15

Which of the following contains phosphorous: DNA, DDT …

DNA

16

Which has a chiral atom: nicotine, pyrrole…

Nicotine

17

Starting unit in terpenes

(C5H8)n

18

Central ion of chlorophyll

Mg

19

Name 3 mycotoxins

Aflatoxins,
Ochratoxins
and Fusarium toxins

20

Name and draw 3 methyl xanthine alkaloids?!

Theophylline, Theobromine and Caffeine

21

Name 3 aroma agents

Miraculin,
curculin and
L-glutamic acid

22

Write the reaction equation for the formation of any nucleotide

Guanine + Ribose + Phosphate = GMP (guaninemonophosphate)

23

Write the dehydration of cholesterol

- OH becomes =O (minus H2O)