Acids and redox Flashcards
what does an acid release in solution?
H+ ions
what does an alkali release in solution?
OH- ions
what is a strong acid? What is the equation?
An acid which completely dissociate in water, non-reversible.
what is a weak acid? What is the equation?
An acid which partially dissolves in solution, reversible
acid equation
HA + aq = A- + H+
What is a base?
A compound which neutralises an acid to form a salt
what is a salt?
a compound formed when the H+ ion(s) from an acid have been replaced by a metal ion or ammonium ion.
what is a monobasic acid?
an acid which only has one H+ ion to exchange, and can only form 1 type of salt
what is a dibasic acid?
an acid which can donate 2H+ ions
what is a tribasic acid?
an acid with 3H+ ions to donate
acid + metal
makes hydrogen and salt
acid + base, plus reaction name
water and salt, neutralisation
acid + carbonate
salt, water and carbon dioxide
what is a alkali?
A base that dissolves in water releasing hydroxide ions into the solution
What is a titration?
A technique used to accurately measure the volume of one solution that reacts exactly with another solution.
What are titrations used for?
Finding the concentration of a solution.
Identification of unknown chemicals.
Finding the purity of a substance.
What are concordant results?
Within 0.10 cm^3 of each other.
When can a mean titre be worked out?
When two or more concordant results are obtained.
how to make a standard solution?
1 Weigh the desired amount of solid in a weighing boat
2 Dissolve all the solid in de-ionised water, stirring with a glass rod
3 Without losing a drop, transfer all the solution to a standard flask
4 Rinse out the beaker carefully, pouring everything into the flask
5 Add more de-ionised water up to the mark
6 Stopper and label the flask
7 Agitate the solution by carefully turning it upside down again and again.
8 Re-weigh the empty weighing bottle.
% error calculation
max error / measurement x 100
what must you always do when calculating error?
add the errors!!!
Phenol Phthalein colour change
pink in base and colourless in acid
methyl orange colour change
yellow in base and red in acid
what is an acid
a species which releases H+ ions in solution.
