Acids and Alkalis Flashcards
What is an acid?
An acid is a substance that has been dissolved in a solvent and that has H+ ions and negative ions.
What is an alkali?
An acid is a substance that has been dissolved in a solvent and that has OH- ions and positive ions.
What is the difference between an alkali and a base?
A base can be any substance metal oxide, metal hydroxide or ammonia, but an alkali has to be soluble.
What is an indicator?
An indicator is a substance that turns a different colour based on how acid or alkaline it is.
What colour does methyl orange change in different substances?
It is red in an acid, orange in a neutral substance and yellow in an alkali.
What colour does litmus solution change in different substances?
It is red in an acid, purple in a neutral substance and blue in an alkali.
What colour does phenolphthalein change in different substances?
It is colourless in an acid and in a neutral substance, but it is pink in an alkali.
What colour does universal indicator change in different substances?
In a strong acid, it is red, it then gradually changes towards green in a neutral substance and then purple in a strong alkali.
What does PH measure?
The number of H+ ions in the solution.
What factor must the number of H+ ions increase by in order for the PH do decrease by 1?
A factor of 10.
What is the strength of an acid?
How much the substance dissociates.
What is the concentration of an acid?
The percent of the solution that is acidic.
What is dissociation?
The process where an ionic compound dissolves and the ions separate.
