1. Electrolytes vs Nonelectrolytes
Solutions Part II
Electrolytes vs Nonelectrolytes

2. Electrolytes vs. Nonelectrolytes
When dissolved in water, allows for electrical conductivity, (electron flow).
When dissolved in water, does not allow for electrical conductivity, (electron flow).
Produces ions when dissolved in water.
Does not produce ions when dissolved in water.
Substances which were formed by ionic bonds.
Substances which were form by covalent bonds.
Acids, bases and salts
Sugar
Note: for an electrolyte to conduct electricity, it must be dissolved in water

3. Ionic and Covalent Bonds
Ionic bond → bond between a metal and a non- metal.
The metal loses an electron to get a positive charge.
The nonmetal gains an electron to get a negative charge.
Covalent bond → bond between non-metals sharing electrons to get stable outer shell.

4. Electrolytic Dissociation
Definition: electrolytes are dissolved in water, dissociating from one another to their respective positively and negatively charged ions, allowing for electrical conductivity.
Key thing → the production of ions during dissociation.
No ions, no electrical conductivity.

5. Examples of Electrolytic Dissociation
Salts NaCl(s)→Na+(aq) + Cl-(aq) CaCl2(s)→Ca2+(aq) + 2Cl-(aq) Acids H2SO4(s)→2H+(aq) + SO42-(aq) HCl(s)→H+(aq) + Cl-(aq) Bases KOH(s)→K+(aq) + OH-(aq) NaOH(s)→Na+(aq) + OH-(aq)

6. Acids
An acid is a substance that releases H+ ions in an aqueous solution.
How can you tell an acid from its chemical formula?
Usually an acid starts with an H atom and is then followed by a non-metal.
Exception! Acetic acid CH3COOH dissociates to H+ and CH3COO-
Acids react with blue litmus paper and turns it red.

7. Bases
A base is a substance that releases OH- ions in an aqueous solution.
How can you tell an acid from its chemical formula?
Usually a base starts with a metal and ends with OH.
Exception! Ammonia NH3 is actually a base even though it doesn’t have an OH- group.
When it reacts with water, the following reaction occurs
NH3 + H2O → NH4+ + OH-
Bases react with red litmus paper and turns it blue.

8. Salts
A salt is a substance that is produced by chemical bonding of a metal and a non-metal other than H+ or OH-.
It is an ionic bond.
NaCl: Sodium chloride dissociates to Na+ and Cl-
KBr: Potassium bromide dissociates to K+ and Br-
BeS: Beryllium sulfide dissociates to Be2+ and S2-
Litmus paper has no effect on salts.

9. Acids Bases Salts Definition Litmus Paper Test Uses/found in
Substance that, when dissociated, releases H+ in solution.
Substance that, when dissociated, releases OH- in solution.
When dissociated, you will have a metal and a nonmetal.
Litmus Paper Test
Turns blue paper red.
Turns red paper blue.
Does not affect litmus paper.
Uses/found in
Neutralizes base, found in fruits.
Neutralizes acid, found in blood, cleaning products.
Found in fertilizers, soaps.
How to Recognize
Usually starts with H, has H+ group.
Usually ends with OH, has OH- group.
1st = metal
2nd= non-metal
Examples
HCl, HF, HNO3
NaOH, Ca(OH)2
NaCl, AgNO3
Exceptions to “H” rule
Water, Acetic Acid (CH3COOH)
CH3OH, C2H50H -> alcohols, not bases, NH₃ is a base.

10. pH Scale
Used to determine whether or not a substance in solution is an acid, a base, or neutral.
Goes from 0 to 14
→ acids
Strong acids closer to 0.
Weak acids near 6.9.
→ bases
Strong bases closer to 14.
Weak bases near 7.1.

11. pH Scale The scale goes up by a 10-fold factor.
Meaning if you are comparing an acid with a pH 2 and pH of 3, the acid which has a pH 2 is 10 times stronger.
If you are comparing an acid with pH 2 and pH 6, the acid which has pH 2 is 104 times stronger.

12. How to Identify Acids, Bases and Neutral Substances
Litmus Paper Test
Tells you if your substance is an acid, base or neutral.
Buffer Solution + Indicators
A buffer solution is a solution composed of a weak acid and its associated base.
Key: its pH changes very little when strong acid/base added to it, meaning it has specific pH levels.
An indicator is a chemical which undergoes a colour change at specific pH’s.

13. Litmus Paper Test Acid Base Neutral Red Litmus Paper Stays red
Turns blue
Blue Litmus Paper
Turns red
Stays blue
Acids are red, bases are blue, (distilled) water is neutral, how about you?

14. Buffer Solution + Indicator
This procedure plays on the specificity of buffer solutions.
The first step you do is introduce your solution to the indicator and record that colour.
Then you introduce your indicator to buffer solutions ranging from pH 1 to pH 14 and match the colour.
You may have to use more than one indicator, for their ranges overlap, thus allowing to get a more precise pH value.

15. pH indicator example pH 1 2 3 4 5 6 7 8 9 10 11 12 13 Thymol Blue
Red Yellow Blue
Bromo. Blue
Yellow Purple
Methyl Red
Red Yellow
Phenol Red
Yellow Red
Cresol Red
Yellow Reddish-Purple
Pheno.
Colourless Fuchsia
Thymol.
Colourless Blue

16. pH Indicator Example
Which indicator(s) would you use to find a strong acid? Strong base? Neutral substance?
My solution turned red using Methyl Red and purple using Bromophenol Blue. What’s the pH of my solution (range)?
My solution turned blue using Thymol Blue and fuchsia using Phenolphthalein. What’s the pH of my solution (range)?

17. Mnemonic to remember for acids and bases
Acids are red, bases are blue, water is neutral, what about you? Acid → turn blue litmus paper red Bases → turn red litmus paper blue Water → as a neutral substance, does not rnx with litmus paper (same as salts)