C8 - Acids, Bases, and Salts Flashcards
What pH value(s) are acidic?
<7
What pH value(s) are alkaline?
> 7
What pH value(s) are neutral?
7
What color does universal indicator litmus turn in acidic and alkaline solutions?
Acidic - red
Alkaline - blue
What color does red litmus turn in acidic and alkaline solutions?
Acidic - red
Alkaline - blue
What color does blue litmus turn in acidic and alkaline solutions?
Acidic - red
Alkaline - blue
What color does phenolphthalein turn in acidic and alkaline solutions?
Acidic - colorless
Alkaline - pink
What color does methyl orange turn in acidic and alkaline solutions?
Acidic - pink/red
Alkaline - yellow/orange
What does a metal + acid reaction make?
salt + hydrogen
What does an acid + base reaction make?
salt + water
What does a metal oxide + acid reaction make?
salt + water
What does a metal carbonate + acid reaction make?
salt + water + carbon dioxide
What is the formula for concentration?
Concentration = Amount of compound/Volume
Are non-metal oxides acidic or alkaline?
acidic.
What is the test for hydrogen?
a lit splint will combust with a (squeaky) pop
What is the test for oxygen?
a glowing splint will relight
What is the test for ammonia?
turns damp red litmus paper blue - also has a pungent odor
What is the test for chlorine?
turns damp blue litmus paper red
What is the test for carbon dioxide?
turns limewater cloudy/milky
What is the difference between a dilute acid/alkali and a concentrated acid/alkali?
A dilute acid alkali has a lower particle to volume ration than a concentrated acid/alkali.
What is the difference between a strong acid/alkali and a weak acid/alkali?
A strong acid/alkali is highly dissociated and a weak acid/alkali is partially dissociated.
What does an ammonium salt + base reaction make?
salt + water + ammonia
How to create an ionic equation?
Balanced equation > add charges > remove spectator ions > ionic equation
What are the 3 methods for preparing/making salts?
- Precipitation
- Titration
- Reaction of acids with excess insoluble substances
Are sodium, potassium, and ammonium soluble?
yes
Are nitrates soluble?
yes
Are common chlorides soluble?
All soluble except for lead and silver.
Are common sulfates soluble?
All soluble except for lead, barium, and calcium.
Are common carbonates and hydroxides soluble?
All insoluble except sodium, potassium, and ammonium.
How to make insoluble salts using the precipitation method? [4]
- Mix chemicals/solutions.
- Filter it.
- Wash the filtered precipitate.
- Leave it to dry.
How to make salts using the excess solid method? [4]
- Add insoluble compound to heated acid.
- Filter the solution.
- Place in evaporating dish and heat it.
- Let it evaporate and leave the crystals.
How to make salts using the titration method? [4]
- Start with the base that has an indicator in it (phenolphthalein)
- Add an acid from a biurette until the solution is colorless
- Gently heat the solution to evaporate the water
- Leave to crystallize.
What is the formula for concentration that involves moles?
Concentration = No. of moles/Volume
What are the metals and their corresponding colors for the cation test?
Crimson/red - lithium
Orange/red - calcium
Yellow - Sodium
Green - Copper (II)
Lilac - Potassium
What are salts?
Ionic compounds.
What is the difference between a base and an alkali?
An alkali is a base that is soluble in water.
What type of reaction is an acid + base?
Neutralisation.
Why are alkalis added to soil?
To neutralise the soil if it is too acidic so that crops can grow.
What happens when aluminum reacts with aqueous sodium hydroxide?
White precipitation, soluble in excess giving a colorless solution.
What happens when aluminum reacts with aqueous ammonia?
White precipitation, insoluble in excess.
What happens when zinc reacts with aqueous sodium hydroxide?
White precipitation, soluble in excess giving a colorless solution.
What happens when zinc reacts with aqueous ammonia?
White precipitation, soluble in excess giving a colorless solution.
What happens when calcium reacts with aqueous sodium hydroxide?
White precipitation, insoluble in excess.
What happens when calcium reacts with aqueous ammonia?
No precipitation or a very slight white precipitation.
What happens when copper (II) reacts with aqueous sodium hydroxide?
Light blue precipitation, insoluble in excess.
What happens when copper (II) reacts with aqueous ammonia?
Light blue precipitation, soluble in excess giving a dark blue solution.
What happens when chromium reacts with aqueous sodium hydroxide?
Green precipitation, soluble in excess.
What happens when chromium reacts with aqueous ammonia?
