11 - Acids and Bases

Question 1

What are acids?

Answer 1

• Acids are compounds that produce H+ ions when dissolved in water.
• It is also known as a proton donor because it donates H+ ions to the base.

Question 2

What is the pH of acids?

Answer 2

1-6.

Question 3

What determines the pH of a compound?

Answer 3

The concentration of H+ ions and OH- ions per dm3. H+ ions decrease the pH and OH- ions increase the pH.

Question 4

What is the difference between strong and weak acids?

Answer 4

Strong acids fully disassociate in an aqueous solution producing many H+ ions, but weak acids partially disassociate in an aqueous solution produces only a few H+ ions.

Question 5

What are bases?

Answer 5

• Bases are compounds that neutralize acids to produce salt and water only.
• They are known to be proton acceptors because it accepts H+ ions from the acids.

Question 6

What is the pH of bases?

Answer 6

8-14

Question 7

What is the difference between strong bases and weak bases?

Answer 7

Strong bases fully disassociate in an aqueous solution, but weak bases partially disassociate.

Question 8

State the 5 different indicators and their effect on acids and alkaline compounds.

Answer 8

1. Phenolphthalein [acid = colorless], [alkaline = pink]
2. Methyl Orange [acid = Pink], [alkaline = Yellow]
3. Methyl Red [acid = Red], [alkaline = Yellow]
4. Red Litmus [acid = Red], [alkaline = Blue]
5. Blue Litmus [acid = Red], [alkaline = Blue]

Question 9

State 4 main acids

Answer 9

hcl
hno3
h2so4
ch3cooh

Question 10

State 4 main alkaline

Answer 10

naoh
koh
ca(oh)2
nh3

Question 11

What are all the types of oxides?

Answer 11

1. Basic Oxides = Metal Oxides
2. Acidic Oxides = Non Metal Oxides
3. Neutral Oxides = Neither alkaline or acidic such as h20 and co
4. Amphoteric Oxides = Zinc and Aluminum Oxides

Question 12

Acid + Metal -> …

Answer 12

Salt + h2

Question 13

Acid + Metal oxide (base) -> …

Answer 13

Salt + h2o

Question 14

Acid + Metal hydroxide (base) -> …

Answer 14

Salt + h2o

Question 15

Acid + Metal Carbonate -> …

Answer 15

Salt + h20 + co2

Question 16

Acid + Metal Hydrogen Carbonate -> …

Answer 16

Salt + h20 + co2

Question 17

State which substances are soluble and which are not

Answer 17

1. Sodium, Ammonium, and Potassium = ALWAYS SOLUBLE
2. Nitrates = Soluble
3. Sulfates = Soluble except for calcium, lead, and barium
4. Chlorides = Soluble except for silver and lead
5. Carbonates = Insoluble except Sodium Ammonium and Potassium
6. Hydroxides = Insoluble except Sodium Ammonium and Potassium

Question 18

State the ways to make salts

Answer 18

1.Using excess metals
- Add excess metal to acid and wait until bubbling stops (hydrogen).
- Filter when finished

2. Using Insoluble Bases
   - Add insoluble into acid and heat gently.
   - Add more until the insoluble base stops dissolving
   - Filter
3. Using alkali by titration
   - Put alkali in flask
   - Add phenolphthalein as an indicator, turning alkali pink
   - Add acid using burette until colorless
   - Repeat until accurate
   - Evaporate water from solution

Question 19

How to make insoluble salts?

Answer 19

Using precipitation which is the mixture of 2 soluble salts

Filter to get insoluble salt and wash in filter paper

Dry in warm oven