acids and redox- chapter 4 Flashcards
what is a strong acid
releases all its hydrogen atoms in solution as H+ ions and completely dissociates in an aqueous solution
what is a weak acid
only releases a small proportion of its available hydrogen atoms into solution as H+ ions, only partially dissociates in an aqueous solution
what does a base do
neutralises an acid to form a salt
name 4 bases
metal oxides
metal hydroxides
metal carbonates
ammonia
what is an alkali
a base that dissolves in water releasing hydroxide ions into the solution
what happens during the neutralisation of an acid
H+ ions react with a base to form a salt and neutral water. the H+ ions from the acid are replaced by metal or ammonium ions from the base
what is an acid neutralised by to form
a metal oxide or metal hydroxides to form a salt and water
acid(aq)+alkali(aq)=
salt(aq)+water(l)
carbonates(s)+acid(aq)
salt(aq)+water(l)+carbon dioxide(g)
what is a titration
a technique used to accurately measure the volume of one solution that reacts exactly with another solution, they can be used for finding concentration, identification of unknown chemicals and finding the purity of a substance
what is a standard solution
a solution of known concentration
what does a volumetric flask do
used to make up a standard solution very accurately
what happens in an acid base titration
a solution of an acid is titrated against a solution of a base using a pipettes and burette
what is the oxidation number
based on a set of rules that apply to atoms, and can be thought of as the number of electrons involved in bonding to a different element
what is the oxidation number for elements
zero
what is the sum of oxidation numbers
total charge
what is oxidation
additional of oxygen
what is reduction
removal of oxygen
what do redox reactions involve
reduction and oxidation
what is reduction in terms of electrons
gain of electrons
what is oxidation in terms of electrons
loss of electrons
what is reduction in terms of oxidation numbers
decrease in oxidation number
what is oxidation in terms of oxidation numbers
an increase in oxidation number
metal+acid=
and when the acid is dilute what reaction is it
salt+hydrogen
redox reactions
