Chemistry

Question 1

Antacid

Answer 1

A weak base

Question 2

Arrhenius Theory

Answer 2

Acid - proton donor

Base - hydroxyl donor

Question 3

Brønsted-lowry theory

Answer 3

Acid - proton donator
Base - proton acceptor
Water is amphoteric
Strong acid- strong tendency to give up proton
Weak acid- weak tendency to give up proton

Question 4

Lewis theory

Answer 4

Lewis acid - electron pair acceptor
Lewis base - electron pair donor
Both combine to make adduct
Uses valence electron (outer e-)

Question 5

pH and [H3O+] equation?

Answer 5

pH= -log[H3O+] 
[H3O+]= 10-pH

Question 6

Kw equation and what is it at 25°C?

Answer 6

Kw= [H3O+][OH-]

25°C kw is 1x10-14

Question 7

Strong acids? Strong base?

Answer 7

HCL HBr HI H2SO4

NaOH KOH

Question 8

Weak acid? Weak base?

Answer 8

Acetic acid (ethanoic acid) HF H2O

NH3 HS- H2O

Question 9

Ka and pKa equation?

Answer 9

Ka= [H3O+][A-] ÷ [HA]

pKa= -logKa Ka= 10-pKa

Question 10

Acid strength of pKa?

Answer 10

The stronget the acid the lower the pKa

The weaker the acid the higher the pKa

Question 11

pH and pKa ionisation?

Answer 11

Acids
pH = pKa 50% ionized 
pH = pKa +1 90%
pH = pKa +2 99%
pH = pKa +3 99.9%

Base
pH = pKa 50% 
pH = pKa -1 90%
pH = pKa -2 99%
pH = pKa -3 99.9%

Question 12

What is pKa?

Answer 12

Measure of how easily a molecule will release a proton

Question 13

Electronegativity?

Answer 13

The ability of an atom to pull bonding electrons towards itself. F is most electronegative

Question 14

Hybridization

Answer 14

Promoting an electron to an empty p orbital to form an sp3 orbital

2e- = linear = 180° = sp 
3e- = trigonal planar = 120° = sp2 
4e- = tetrahedral = 109.5° = sp3 

Single bond is sigma
Double bond is one sigma and one pie bond

Question 15

Buffer?

Answer 15

The ability to resist changes in pH upon the addition of small amounts of either acid or base
Equivalence point is when the pH and Base are at the same point

Question 16

Henderson Hasselbalch equation

Answer 16

pH = pKa + log ([conjugate base] ÷ [acid])

Question 17

Alkane pKa

Answer 17

> 50

Question 18

Alkynes pKa

Answer 18

44

Question 19

First law of thermodynamics

Answer 19

Energy can’t be created or destroyed, it can only be converted from one form to another

Question 20

Energy equation

Answer 20

Change in energy = final - initial

Question 21

Exothermic and Endothermic

Answer 21

A change that releases heat = decrease in enthalpy (negative number)

A change that absorbs heat = increase in enthalpy (positive number)

Question 22

Heat capacity equation

Answer 22

Q= C x change in T

Question 23

Rate equation and arrhenius equation

Answer 23

Rate = k[A]n[B]m

K = Ae^(-Ea/RT)

Question 23

Alcohol pKa

Answer 23

15.5-18

Water is 15.7

Question 24

How to prioritise atoms attached naming it R/S?

Answer 24

``` Drawn in 3D Prioritise using atomic number Make sure 4th atom at back Clockwise = R Anticlockwise = S ```

Question 25

2 exceptions for enantomers?

Answer 25

Plane polarised light filters it Optical activity

Question 26

Meso stereoisomers

Answer 26

Molecules with 2 identical chiral carbon atoms have 3 stereoisomers

Question 27

Separating enantiomers?

Answer 27

Resolution- separation from racemic mixture or enantiomerically enriched mixture. One crystallised and filtered and other evaporated Chiral chromatography- racemic solution is passed over chiral stationary phase giving rapid and reversible diastereotopic interaction

Question 28

Lipinski rule?

Answer 28

No more than 5 h bond donors No more than 10 h bond acceptors Molecular weight under 500 dalton's Partition coefficient log P less than 5 Used for assessing drug likeness and suitability for oral administration

Question 29

Phenol pKa

Answer 29

10

Question 30

Carboxylic acid pKa

Answer 30

4.8

Question 31

Anomer

Answer 31

2 sugars that's differ in configuration at the carbon that's the C=O in the open chain form

Question 32

Separation of amino acids?

Answer 32

pI separation by electrophoresis By polarity - chromatography In exchange chromatography

Question 33

Amide pKa

Answer 33

Neutral 35 | RCO2H 5

Question 34

Semi-synthetic substance

Answer 34

Some compounds either can not be purely synthesized or can not be isolated from natural sources in low cost. Therefore, the natural intermediate of such drugs could be used for the synthesis of a desired product

Question 35

HCl pKa

Answer 35

-7

Question 36

Inductive effect

Answer 36

An atoms ability to polarise a bond | can cause polarisation

Question 37

pH of abdomen

Answer 37

Stomach - 1-3 Small intestines - 6-7.5 Large intestines - 7-8 Colon - 5-7

Question 38

Carboxylic derivative reactivity order

Answer 38

``` OH (carboxylic acid) Cl (acid chloride) OC(O)R' (anhydride) OR' (ester) NR2 (amide) ```

Question 39

water pKa

Answer 39

15.7

Question 40

H3O pKa

Answer 40

-1.7

Question 41

Single, double and triple

Answer 41

Single - sigma Double - 1 sigma, 1 pie Triple - 1 sigma, 2 pie

Question 42

SN1 vs SN2

Answer 42

SN1 forms and intermediate whereas SN2 doesn't

Question 43

Second law of thermodynamics

Answer 43

Entropy of the universe increases in a spontaneous process and remains unchanged in an equilibrium process

Question 44

HLB

Answer 44

more soluble in water if more than 10