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Flashcards in C2f Deck (12):

How can universal indicator be used to estimate the pH of a solution?

It changes colour.


What are the colour changes with litmus?

Red = acid
Blue = alkali


What do indicators use colour changes to show?

Sudden or gradual changes in pH.
colour changes over different pH ranges.


What is an alkali?

A soluble base.


What is the word equation for neutralisation?

acid + base = salt + water


What do all acids in solution contain?

H+ ions.


What is the pH of an acid determined by?

The concentration of H+ ions.


Why is an acid neutralised by an alkali?

acids contains H+ ions.
alkalis contains OH- ions
neutralisation involves the reaction H+ + OH- = H2O


What can an acid be neutralised by?

An alkali or base.


Why do metal oxides and metal hydroxides neutralise acids?

Some dissolve in water. These soluble compounds are alkalis. even bases that won't dissolve in water will still react with acids. So, all metal oxides and hydroxides react with acids to form a salt and water because they are bases.


What do carbonates neutralise?

Acids, to give water, a salt and carbon dioxide.


What is the name of the salt produced when a base or carbonate is neutralised by a laboratory acid?

Sulfuric acid = sulfate = H2SO4
Nitric acid = nitrate = HNO3
Hydrochloric acid = chloride = HCl
Phosphoric acid = Phosphate = H3PO4