acids, alkalis and titrations Flashcards
What pH is strongest acid and alkali?
- acid=0
- alkali=14
What are indicators used for?
-estimating the pH of a solution
What is universal indicator and what is it used for?
- combination of dyes which give all the colours
- used to find the pH of an aqueous solution
what is litmus paper used for?
- tests whether a solution is acidic or alkaline because it changes colour around pH 7
- red in acidic solutions, purple in neutral and blue in alkaline
what is phenolphthalein used for?
-changes from colourless in acidic solutions to bright pink in alkaline solutions
what is methly orange used for?
-changes from red in acidic solutions to yellow in alkaline solutions
What can acids be neutralised with?
-bases
What is a base?
-a substance that can neutralise an acid. They are proton acceptors and acids are proton donors
What is an acid?
-a source of hydrogen ions (H+)
What is an alkali?
-a source of hydroxide ions (OH-)
What happens when an acid neutralises a base?
-the products are neutral
What is produced when acid reacts with bases?
-salt + water
What salt does hydrochloric acid produce?
-chloride salts
What salt does sulfuric acid produce?
-sulfate salts
What salt does nitric acid produce?
-nitrate salts
Which reactions form salt + water?
- acid + metal oxide
- acid + metal hydroxide
What reaction forms ammonium salt?
-acid + ammonia
What reaction forms salt+water+carbon dioxide?
-acid + metal carbonate
Soluble or insoluble?
-common salts of sodium, potassium and ammonium
-soluble
Soluble or insoluble?
-nitrates
soluble
Soluble or insoluble?
common chlorides
-soluble except silver chloride and lead chloride
Soluble or insoluble?
common sulfates
-soluble except lead, barium, calcium sulfate
Soluble or insoluble?
common carbonates
-insoluble except sodium, potassium, ammonium
Soluble or insoluble?
common hydroxides
-insoluble except sodium, potassium, calcium
How can u make a soluble salt?
-by reacting an acid that contains one of the ions you want in the salt with an insoluble base that contains the other ion you need
Steps for making a soluble salt (5)
- heat the acid in a water bath which speeds the reaction between acid and insoluble base. Do this in fume cupboard
- add the base to acid-will react to produce a soluble salt + water
- filter off the excess solid to get a solution containing salt and water
- heat the solution gently using bunsen to slowly evaporate some water. Leave solution to cool and allow salt to crystallise
