Water Analysis Part 5 Flashcards
What is the pH scale used to determined and what is its range?
Whether a solution is acidic or alkaline, ranges from 0-14
What do neutral solutions measure on the pH scale?
7
What do strong acids, moderate acids and weak acids measure on the pH scale?
Strong acids = 0-2
Moderate acids = 3-4
Weak acids = 5-6
What do weak alkalis, moderate alkalis and strong alkalis measure on the pH scale?
Weak alkalis = 8-9
Moderate alkalis = 10-11
Strong alkalis = 12-14
What are indicators?
Plant dyes which change colour in acidic or alkaline solutions, used to measure the pH of solutions
What is universal indicator?
A blend of many dyes to produce a range of colours that change through the entire pH range
What is a base?
Any compound that can neutralise an acid
What is said to happen when acids react with bases?
They are said to neutralise
What do neutralisation reactions always produce?
A salt and water
What are salts?
Ionic compounds that result from the neutralisation reaction of an acid and a base
Acid + Metal Oxide =
Metal Salt + Water
Acid + Metal Hydroxide =
Metal Salt + Water
Acid + Metal Carbonate =
Metal Salt + Water + Carbon Dioxide
Acid + Metal Hydrogen Carbonate =
Metal Salt + Water + Carbon Dioxide
Acid + Ammonia Solution =
Ammonium Salt + Water
What are spectator ions?
Ions which are not involved in the actual reaction during ionic precipitation reactions
What are acids?
Substances that dissolve in water to produce hydrogen ions
What do acids donate when they react and what does that mean about acids?
They donate hydrogen ions, therefore all acids must contain hydrogen atoms
What does carbonate produce when it reacts with acid?
A gas
Why is water called the universal solvent?
Because of its ability to dissolve a great variety of substances
