10 Flashcards
1
Q
Hydration
A
- positive ends of water molecule are attracted to negatively charged anions
- negative ends are attracted to positively charged cations
- this happens when water has salt or something in it
- it breaks up INDIVIDUAL cation and anions
2
Q
Solubility
A
- ability of a substance to dissolve into a solvent
- differences in solubilities of IONIC compounds in water depends on relative attractions of the ions for each other (forces hold the solid together) and attractions of ions for water molecules
- all NITRATES are soluble in water
- water can dissolve NONIONIC substances
- in general, polar and ionic substances are expected to be more soluble in water than nonpolar substances
3
Q
Solute
A
-substance being dissolved
4
Q
Solvent
A
-substance dissolving the solute (water)
5
Q
Electrical conductivity
A
-ability to conduct an electric current
6
Q
Electrolyte
A
-substance that when dissolved in water produces a solution that can conduct electricity
7
Q
Svante Arrhenius
A
- believed that the conductivity of solutions arose from the presence of ions (how many ions they created in aqueous solutions)
- believed acids provide a hydrogen ion (positive, H+) and are sour
- believed bases provide a hydrogen ion (negative, OH-)
8
Q
Strong Electrolytes
A
- there are three classes : soluble salts, strong acids, strong bases
- salt (cations and anions) separate in water
9
Q
Strong Acids
A
- when they are in water, virtually every molecule ionizes
- sulfuric acid, nitric acid, and hydrochloric acids are aqueous and should be written like HCl(aq)
- since strong acids completely dissociate into its ions, 100 molecules of HCl dissolved in water will created 100 H+ ions and 100 Cl- ions
- H2SO4 says that this acid can produce 2 H+ ions per molecule when dissolved in water, but only the first H+ ion is completely broken down. The second H+ ion can be pulled off under certain conditions. Therefore, H2SO4 contains mostly H+ and H2SO4- ions.
10
Q
Strong Bases
A
- soluble ionic compounds
- have hydroxide ion (OH-)
- when in water, OH- ions separate and move independently
- bitter and slippery
11
Q
List of Strong Acids
A
- HCl, hydrochloric
- H2SO4, sulfuric
- HBr, hydrobromic
- HI, hydroiodic
- HNO3, nitric
- HClO4, perchloric
12
Q
Weak Electrolytes
A
- acetic acids is a weak acid
- ammonia is a weak base
13
Q
Acetic Acids:
A
- formula for acids are often written with acidic hydrogen atoms or atoms (produce H+ ions) first and non acidic hydrogens later
- double arrow means that the reaction can occur in either direction
- it is a weak acid
14
Q
Weak Acid
A
-any acid that dissociate (ionizes) only to a slight extent in an aqueous solution
15
Q
Weak Base
A
- ammonia is one
- resulting solution is a weak electrolyte (few ions are formed)
- OH- ions are also formed
16
Q
Nonelectrolytes
A
- substances that dissolve in water but do not produce any ions
- ethanol is one (molecules do not break up into ions)
- table sugar (sucrose)
17
Q
Molarity
A
- number mol solute/liters of solution
- measure of concentration
18
Q
Solubility rules:
A
- all nitrates are soluble (NO3-)
- all alkali metals and ammonium salts are soluble (NH4+) (first column)
- all chlorides, bromides, and iodides are soluble except : Pb2+, Ag+, Hg2+
- all sulfates (SO42-) are soluble except Pb2+, Ag+, Hg22+, Ca2+, Sr 2+, Ba2+
- everything else is not soluble unless mr. william tells us otherwise
19
Q
Spectator ions
A
things that don’t react
20
Q
List of Strong Bases:
A
- LiOH
- NaOH
- KOH
- Ca(OH)2
- SR(OH)2
- Ba(OH)2
21
Q
Three types of reactions
A
- double displacement/precipitation reaction
- acid base reaction / water forming
22
Q
Double displacement/precipitation reaction:
A
- characterized by AX + BY –> AY + BX
- switching partners
23
Q
Acid base reaction / water forming
A
- acid and base combining
- characterized by AX + BY –> AY + BX, like double displacement
- creates water
24
Q
net ionic equation
A
crossing out spectator ions
25
formal equation
you show the switching
26
complete ionic eqution
formal with adding together
27
oxidation
loss of electrons
28
reduction
gain of electrons
| positive charge getting lost
29
oxidation state
charge on the atom, works only for ionic not molecular
30
rules of oxidation state
1. everything by itself in natural occurring state has a O charge
2. oxygen COMPOUNDS are always 2- EXCEPT in peroxide (H2O2) where it is 1-
3. hydrogen is always 1+ unless you are told otherwise
4. everything else can be deduced from what you know
31
N
can be expressed as 10 to the X
ex:
- 100 is x = 2
- 10 is x = 1
32
using Log
```
LogN = x
ex:
-65 is x = ?
-Log65 = x
= 1.81
```
33
[A]
concentration of "A' in molarity
ex:
[H+] is the concentration of H+ in molarity
34
to find the pH using log
```
pH = -log[H+]
ex:
1. find concentration of H+
2. the concentration of H+ is the same as HCl which is 6
3. [H+] is 6
4. plug in
```
35
what is pH typically between
0 (acidic) - 14 (basic)
36
what is H30+
- it is the same as H+
- H+ is just a proton and very small
- H+ then just latches onto H20, creating H30+
37
in the classic titration lab..
we are just adding NaOH to get HCl nneutralized
| -at a 1 to 1 ratio
38
using molarity to find moles
- n = mv
- na = mava
- nb= mbvb
- since na and nb are equal: mava=mbvb
- in the classic titration lab we are trying to find ma
39
Dilution
- adding water to achieve molarity desired for particular solution
- moles of solute after dilution = moles of solute before dilution
40
Precipitation Reaction / Double displacement
- when two solutions are mixed, an insoluble substance sometime forms / a solid forms and separates from the solution
- remember: when ionic compounds dissolve in water, the resulting solution contains the separated ions
41
slightly soluble
- tiny amount of solid that dissolve is not noticeable
| - the solid appears to be insoluble to the naked eye
42
Formula equation
- shows reactants and products of reaction
| - does not give correct picture of what actually occurs in the solution
43
complete ionic equation
- all substances that are strong electrolytes are represented as ions
- reveals that only some of the ions participate in the reaction
- spectator ions are written as separate ions
- but solids are not written as separate ions
44
net ionic equation
-only shows solution components directly involved in the reaction
45
Solving Stoichiometry Problems for Reactions in Solutions
- identify species present in the combined solution, and determine what reaction occurs
- write balanced net ionic equation for reaction
- calculate moles of reactants
- determine which reactant is limiting
- calculate moles of product or products
- convert to grams or other units
46
indicator
- equivalence point or stoichiometric point is marked by this
- it changes color at the equivalence point
47
endpoint
-the point where the indicator actually changes color
48
Requirements for a successful titration
- the exact reaction between titrant and analyte must be known (and rapid)
- the stoichiometric point must be marked accurately
- volume of titrant required to reach stoichiometric point must be known accurately
49
covalent bonds
-electrons are shared
50
cations
positive
51
anions
negative
52
electrolytes
substances that conduct electricity when dissolved in whatever
