DONT STUDY THIS Flashcards
What is an acid in regards to pH?
substance with ph less than 7
What ions do acids form in water?
H^+ ions
What can we say about concentration of hydrogen ions in a solution compared to acidity and pH?
The higher concentration of hydrogen ions in the solution, the more acidic it is, the lower the pH is
What is a base?
A substance that reacts with an acid to produce a salt and water
What is an alkali?
A base that is soluble in water
What pH do alkalis have?
Greater than 7
What ions do alkalis form in water?
OH^- ions (hydroxide ions)
What can we say about concentration of hydroxide ions in a alkaline solution compared to pH?
Higher concentration of OH^- ions, higher the pH
What is an Indictator?
A dye that changes colour depending on whether it’s above or below a certain pH
How do you use an indicator?
Add a few drops to the solution you’re testing, and compare the colour the solution goes to the pH chart for that indicator
Universal indicator is added to a strong acid. What colour does it turn?
Dark red
Universal indicator is added to a mild acid. What colour does it turn?
Orange
Universal indicator is added to a weak acid. What colour does it turn?
Yellow
Universal indicator is added to a neutral substance. What colour does it turn?
Green
Universal indicator is added to a weak alkali. What colour does it turn?
Dark blue
Universal indicator is added to a mild acid. What colour does it turn?
Blue/purple
Universal indicator is added to a weak alkali. What colour does it turn?
Purple/pink
What are the four indicators?
Universal Indicator, litmus, methyl orange, phenolphthalein
What colour does litmus turn in acidic, neutral and alkaline solutions?
Acidic=red
Neutral=purple
Alkaline=blue
What colour does methyl orange turn in acidic, neutral and alkaline solutions?
Acidic =red
Neutral = yellow
Alkaline = yellow
What colour does phenolphthalein turn in acidic, neutral and alkaline solutions?
Acidic = colourless Neutral = colourless Alkaline = pink
What is the reaction between an acid and base called? What does it produce?
Neutralisation reaction, salt and water
Acid + base > ?
Salt + water
What can neutralisation reactions in aqueous solutions be shown as?
An ionic equation in terms of H^+ and OH^- ions