Acids and Bases Flashcards
What is an acid?
A substance with a pH less than 7.
What is an alkali?
A base that is soluble in water, with a pH more than 7.
What do acids form in water?
H+ ions.
What do alkalies form in water?
OH− ions.
As the concentration of H+ ions increases, what changes?
The pH decreases (acidic solution).
As the concentration of OH− ions increases, what changes?
The pH increases (alkaline solution).
What colours does litmus paper turn?
Red in acidic, purple in neutral, and blue in alkaline solutions.
What colours does methyl orange turn?
Red in acidic, and yellow in neutral and alkaline solutions.
What colours does phenolphthalein turn?
Colourless in acidic and neutral, and pink in alkaline solutions.
What are the products of a neutralisation reaction?
Salt and water.
What is the equation for neutralisation reactions?
HCl + NaOH → NaCl + H2O
acid + base → salt + water
What is the ionic equation for neutralisation reactions?
H+ (aq) + OH− (aq) → H2O (l)
