Acids and Bases Flashcards
What are the 3 physical properties of acids?
- Acids have a sour taste.
- Acids are electrolytes. They ionise to form mobile ions when dissolved in water, which act as mobile charge carriers to conduct electricity.
- Acids have a pH of below 7. (turn blue litmus paper red).
What do acids react with bases to form?
Salt and water in a neutralisation reaction.
What do acids react with reactive metals to form?
A salt and a hydrogen gas.
What do acids react with carbonate to form?
A salt, water, and carbon dioxide gas.
What metals are unreactive metals? (do not react with acids)
Cu, Ag, Au
When do acids display their properties?
Only when dissolved in water.
Are all compounds that contain hydrogen acidic?
No. Only molecular compounds that ionise to form hydrogen ions are acidic.
What does the strength of an acid refer to?
The extent of ionisation. (to form hydrogen ions)
What does the concentration of acid refer to?
The amount of it per unit volume.
What are the three types of basicity’s of acids?
Monobasic, Dibasic, Tribasic
How do you test for hydrogen gas?
Place a burning splint at the mouth of the test tube. Hydrogen gas extinguishes the burning splint with a “pop” sound.
How do you test for carbon dioxide gas?
Name one example of a monobasic acid and a dibasic acid.
Monobasic – Hydrochloric acid (HCl)
Dibasic – Sulfuric acid (H2SO4)
Explain why 0.100mol/dm^3 sulfuric acid has a higher concentration of H+ ions than 0.100mol/dm^3 hydrochloric acid.
Sulfuric acid has a higher concentration of H+ ions. Both acids have the same concentration and strengths. However, they have different basicity. Sulfuric acid is dibasic, so it produces 0.200mol/dm^3 of hydrogen ions. Hydrochloric acid is a monobasic acid, so it will produce only 0.100mol/dm^3 of hydrogen ions.
What do bases form when reacted with ammonium salts?
Salt, water, and ammonium salts.
What 2 substances do bases contain?
Oxide ions (O2-)
hydroxide ions (OH-) – produced by alkali
How do you test for ammonia gas?
Ammonia turns a damp red litmus paper blue.
What bases are insoluble?
Copper (II) oxide (CuO), and Iron (III) oxide (Fe2O3)
What are soluble bases also known as?
Alkali
What are the 4 physical properties of alkali?
- Turns red litmus paper blue
- Is an electrolyte
- Feels slippery and soapy
- Tastes bitter
Give an example of a strong alkali and a weak alkali.
Sodium hydroxide (strong), Aqueous ammonia (weak)
What pH range does a strong alkali have and what is its level of dissociation?
pH range of 10-14 and dissociates completely
What pH range does a weak alkali have and what is its level of dissociation?
pH range of 7-10 and dissociates partially
What colour is methyl orange in an acidic solution and alkaline solution?
Red in acidic solution and Yellow in alkaline solution.
Which indicators change colour at the 3-5 pH range?
Methyl orange and screened methyl orange.
What colour is Litmus in acidic solution in alkaline solution?
Red in acidic solution and Blue in alkaline solution.
What pH range does litmus change colour at?
pH 5-8
What colour is Thymolphthalein in acidic and alkaline solutions and what pH range does it change colour in?
Colourless in acidic solution and blue in alkaline solution.
What colour is Bromothymol blue in acidic solution and alkaline solution?
Yellow/pink in acidic solution
green endpoint in alkaline solution.
What colour does a strong acid and weak acid turn Green Universal Indicator?
Strong acid –> Turns red
Weak acid –> Turns yellow/orange
What is the equation to calculate pH?
pH = -lg [H+]
How do you calculate [H+] ions given the pH?
[H+] = 10^whatever the pH is
What does the equivalence point refer to in titration?
The volume of reactants.
What is the purpose of “liming” soil, and what is slaked lime made of?
Increases the pH level of the soil, reducing its acidity. Slaked line is calcium hydroxide.
What are the main elements of fertiliser?
Ammonia and Nitrogen.
What kind of oxides are most metal oxides?
Basic oxides.
What are the properties of basic oxides?
Display basic properties, and are solid at room temperature.
What metal oxides are not basic?
Zinc oxide, Aluminium oxide, Lead oxide.
What kind of oxides are most non-metals?
Acidic oxides.
What are the 4 types of oxides?
- Basic
- Acidic
- Amphoteric
- Neutral
Name 3 neutral oxides?
H2O, CO, NO
How would you determine how to prepare a salt, and how should you prepare it based on these conditions?
Solubility of salt in water, and solubility of the starting materials in water.
Insoluble –> prepared by precipitation
Soluble –> prepared by reactions of acid
What salts cannot be prepared using the RAWIS method?
SPA: Sodium, Potassium, Ammonium
