Acid, Bases, and Salts Flashcards
How to handle explosive chemicals
May explode if handled/ treated incorrectly
How to handle flammable chemicals
Chemical ignites easily - Keep away from sparks and flames.
How to handle toxic chemicals
Take great care when using
Hour to handle corrosive chemicals
Wear glasses + eye protection
Wash off skin
How to handle chemicals with caution symbols
Wear glasses+ eye protection
Wash off skin
What colour is red litmus paper in acid?
Red
What colour is red litmus paper in neutral?
Red
What colour is red litmus paper in alkali?
Blue
What colour is blue litmus paper in acid?
Red
What colour is blue litmus paper in neutral?
Blue
What colour is blue litmus paper in alkali?
Blue
What colour /number on universal indicator is acidic?
0- 6 ( Red, orange, yellow )
————————————->
Increasing acidity
What colour is neutral on the universal indicator and what colour is it?
7 and green
What colour /number on universal indicator is alkaline?
8-14 (blue and purple)
——————————>
Increasing alkalinity
Advantages of these indicators
• universal indicator and litmus paper are cheap
• ph metre gives exact ph value
• universal indicator gives strength and a rough ph value
Disadvantages of these indicators
• PH meters are expensive and can break
• Litmus cannot tell you if it’s strong or weak
Describe acids
• Have ph value below 7
• Sour taste, corrosive
• Release hydrogen ions when dissolved in water, which causes acidity
Describe the ionisation of strong and weak acids
• Strong acids - completely ionise when dissolved in water to form hydrogen ions ( H+)
• weak acids - partially ionise in water to form hydrogen ions ( H +)
Describe alkalis
• PH value above 7
• Caustic, soapy feel
• Release hydroxide ions when dissolved in water, which causes them to be alkaline
Describe the ionisation of strong and weak alkalis
• Strong alkalis = completely ionise when dissolved in water to form hydroxide ions ( OH- )
• Weak alkalis = partially ionise when dissolved in water to form hydroxide ions ( OH- )
What is a base?
A metal oxide or hydroxide that will neutralise an acid
What is an alkali?
A soluble base
What is strength?
a measure of how much the acid or alkali ionises when dissolved in water , measured by ph
What is concentration?
a measure of how many particles there an dissolved in a certain amount of water, measured in mol dm -3
What is neutralisation?
The reaction between the hydrogen ( H +) ions in an acid and the hydroxide (OH-) ions in an alkali to produce water
What is a salt?
Compound formed when some / all of the hydrogen ions of an acid and replaced by metal or ammonium ions
Reaction of acids with metals
Metal + salt → salt + hydrogen
Reactions of acids with bases
Acid + base → salts + water
Reactions of acids with metal carbonates
Metal carbonate+acid → salt + Carbon dioxide + water
Reactions of acids with metal hydrogen carbonates
Metal hydrogen carbonate + acid → salt + carbon dioxide + water
Test for hydrogen gas
Use lit splint for squeaky pop
Test for CO2 gas
Bubble into lime water solution ( colourless to cloudy)
