Flashcards in Topic 4- Chemical Changes Deck (22):
What is a ph scale?
It measures of how acidic or alkaline a solution is.
The pH of an acid or alkali is a measure of the concentration of H+ ions in the solution.
What is a indicator?
It is a dye that changes colour depending in whether it's above or below a certain Ph.
What is an acid?
A acid is a substance that forms aqueous solutions with an Ph of less than 7, acid forms H+ ions in water.
What is a base?
A base is a substance with a pH greater than 7.
What is an alkali?
It is a base that dissolves in water to form a solution with a pH greater than 7. Alkalis forms OH- ions in water.
What is a reaction between acid and bases called?
H+ + OH- = H2O
How can you calculate the concentration of acids or alkali?
What do acids produce in water?
What do strong acids do in water?
They completely ionise in water, all acid particles dissociate to release H+ ions.
Positions of equilibrium:
HCI->H+ + Cl-
What do weak acids do in solution?
They do not fully ionise in solution. Only a small proportion of acid particles dissociate to release H+ ions.
Position of Equilibrium:
CH3COOH<=> H+ + CH3COO-
What do concentration measure?
It measures how much acid there is in a certain volume of a water.
What are examples of base?
Metal Oxides & Metal Hydroxides& Metal Carbonates
Acid + Metal Oxide
Salt + Water
Acid + Metal Hydroxide
Salt + Water
Acid + Metal Carbonates
Salt + Water + Carbon Dioxide
The order of the reactive series:
Acid + Metal
Salt + Hydrogen
Metal + Water
Metal Hydroxide + Hydrogen
Gain of Oxygen
Loss of Oxygen
Ηow would metals above Carbon would be extracted?