chemistry specification part 6

Question 1

Describe how to carry out an acid-alkali titration

Answer 1

-measure out acid using a pipette into a conical flask and add a few drops of indicator
-slowly add alkali to the acid using a burette till you reach the endpoint (when it changes colour)
-then carry out the experiment with the exact same volumes of acid and alkali but without the indicator
-the solution that remains is salt and water only
-evaporate and leave to crystallise

Question 2

Explain why, if soluble salts are prepared from an acid and a soluble reactant titration must be used

Answer 2

you need to work out the exact amount of alkali to neutralise the acid

Question 3

what are electrolytes?

Answer 3

ionic compounds in the molten state
or dissolved in water

Question 4

what is electrolysis?

Answer 4

breaking down/decomposing of a compound using electricity

Question 5

what happens at the cathode

Answer 5

reduction

Question 6

what happens at the anode?

Answer 6

oxidation

Question 7

what is the cathode rule for aqueous solutions?

Answer 7

if H+ ions and metal ions are present, hydrogen gas will be produced if the metal is more reactive, if it is less reactive then the metal will be produced

Question 8

what is the anode rule for aqueous solutions

Answer 8

if hydroxide and halide ions are present, the halide ions will go to the anode. If no halide ions are present then oxygen will be formed.

Question 9

how do metals react in water?

Answer 9

very reactive metals will fizz vigorously, less reactive metals will bubble

Question 10

what is the reactivity series in order from most reactive to least

Answer 10

potassium
sodium
calcium
magnesium
aluminium
carbon
zinc
iron
hydrogen
copper
silver
gold