Chapter 8 - Acid and Alkalis Flashcards
What is neutralisation?
A chemical reaction where an acid and a base produce a solution of neutral pH 7
What is the general word equation for an acid and base ?
Acid + base = salt + water
What pH do acids have? What about alkalines?
Acid pH less than 7, <7
Alkalines pH more than 7, >7
What are bases?
Substances that neutralise acids , they can be soluble bases, alkalines, and other insoluble bases
What are metal oxides?
Insoluble bases, not alkaline
What are hydroxides?
An alkaline base, soluble
What are the main stages of making a soluble salt crystals from dilute sulfuric acid and copper oxide?
Start with a measured volume of acid
Gently heat the acid until almost boiling
Slowly add copper oxide and stir with glass rod, keep adding this until there is excess oxide at the bottom
Remove excess oxide with filter tunnel and paper
Take copper sulfate solution into evaporating basin
Place over Bunsen until half solution is evaporated
Place on widow sill to slowly evaporate and form crystals
What is the general word equation for metal and acid?
Metal + acid = salt + hydrogen
What is the general word equation for metal carbonate and acid?
Metal carbonate + acid = salt + water + carbon dioxide
What is the symbol for carbonate?
CO3
What does diatomic mean?
Chemicals that go around in pairs, e.g. H + Cl
Name the 4 state symbols
Solid (s), gas (g), liquid (l), and aqueous (aq) which means dissolved in water
Alkali does what to the pH? What about acids?
Alkaline increase the pH, acid decreases the Ph
What is the sequence of events to produce a soluble salt from an acid and an alkaline using titration?
Put the acid in the burette (measured amount)
Measure known amount of alkaline in pipette then put this in a conical flask
Add a suitable indicator to the alkali
Slowly add acid from burette whilst stirring
Once alkaline is neutralised (you can see from indicator) measure how much acid that took (from what’s left over)
Repeat this with known amounts and no indicator then evaporate until half way then leave to form salt crystals
What is the name of the method used to to make a salt from an acid and an alkaline?
Titration
What is the acid ion? What about alkaline?
Acid, H+
Alkaline, OH-
What are precipitates?
Solids suspended in a solution, they make the solution cloudy