Acids and bases and reactions Flashcards
Properties of acids
-taste sour
-corrosive
-indicators to change colour
-can conduct electricity
Properties of bases
-taste bitter
-slippery
-corrosive
-react with acids=water
-can conduct electricity
Define indicator
Determine whether a solution is an acid or base
What was arrenhenius’s theory?
Acid dissociates in solutions to produce hydrogen ions
Bases ionise in solutions to produce hydroxide ions
Limitations to the theory
-substances may not have OH formula but can still form OH solutions
-rules on work in solutions in water
-reactions such as HCL+NH3–>NH4CL are unexplained
-not all salts are neutral
Define electrolytes
Liquids that can conduct an electric current
-must form ions to conduct when dissolving in water
Relationship between conc and electric current flow
greater conc of ion= bigger flow of electric current
Ionisation in acids (weak and strong)
strong: all acid molecules are fully ionised
weak: partially ionised
Ionisation in bases (weak and strong)
weak: partially dissociate or ionise
strong: fully ionise or dissociate
Define pH and it’s trends
Measure of a solutions acidity
-generally falls as hydrogen ions increase
-acidic solutions < pH 7
-base solutions > pH 7
-greater acidity = lower pH
-every change in pH = 10 fold change in H+
Types of reactions and their equations
- Neutralisation
acid + water –> salt + water - Acid and metal
acid + water –> salt + hydrogen gas - Acid and carbonate
acid + carbonate –> carbon dioxide + salt + water - Base reaction
acid + ammonium salt –> salt + ammonia + water
strongest acids
-hydrochloric acid
-hydrobromic acid
-chloric acid
-sulfuric acid
-nitric acid
-hydroiodic acid
What is instantaneous rate of reaction?
the change in concentration of an infinitely small time interval.
Define collision theory
For reactions to occur reactant molecules must collide:
-with sufficient activation energy to disrupt bonds
-correct orientation suitable for bond breaking
Define activated complex (look at example graphs)
-highest energy
-bond breaking/forming
-arrangement of atoms is unstable
-exists prior to reaction ending (instant)