acid, base and salts

Question 1

What is the definition of an acid?

Answer 1

Dissociates in water to form H+ ions

Note: a strong acid dissociates fully to form high concentration of H+ ions while a weak acid dissociates partially to form low concentration of H+ ions.
Ie. more acidic more H+

Question 2

What are the 3 chemical reactions an acid is able to undergo?

Answer 2

1. Acid + Metal –> Salt + Hydrogen gas
2. Acid + Base -> Salt + water
3. Acid + Carbonate -> Salt + Water + Carbon dioxide gas

Question 3

Test for hydrogen gas

Answer 3

Extinguish lighted splint with a pop sound

Question 4

Test for Carbon dioxide

Answer 4

Bubble CO2 through limewater. White ppt formed.

Question 5

What is the definition of an alkaline?

Answer 5

Dissociates in water to form OH- ions

Question 6

What are the 2 chemical reactions a base undergoes?

Answer 6

1. Acid + Base -> Salt + water
2. Ammonium salt + base -> salt + water + ammonia gas

Question 7

Test for ammonia gas

Answer 7

Turns moist red litmus paper blue

Note: NH3(g) + H2O -> NH4OH(aq) fun fact: you moist the litmus paper for ammonia gas to dissolve to ammonium hydroxide which is alkaline!

Question 8

What type of reaction is acid+ base reaction?

Answer 8

Neutralisation

Question 9

Salt preparation methods + type of salt it produces(soluble or insoluble)

Answer 9

1. Titration
   - to produce soluble salt
   soluble + soluble -> soluble salt
2. Acid + insoluble -> soluble
   eg. H2SO4 + CuO -> CuSO4 + H2O
3. Precipitation reaction
   - insoluble salt
   soluble + soluble -> insoluble
   Eg. HCL + AgNO3-> AgCL + HNO3

Question 10

Solubility table: What salts are soluble and insoluble

Answer 10

I like to categorise them into 3 sets
1. ALL soluble
- all SPA salts + Group 1
SPA: sodium potassium and ammonium
- all nitrates
2. Mostly soluble some insoluble
- chlorides
exception is AgCL and PbCL2
- sulfates
exception is Barium, Calcium and Lead(Pb)
Big Chubby Piglets!!! sorry it’s a very lame way to remember but it works haha
3. Mostly insoluble some soluble
- carbonates
- hydroxides/ oxides
exceptions are SPA + Group 1