chemical changes

Question 1

what is the reactivity series

Answer 1

league table for metals the more reactive metals are near the top of the table with the least reactive near the bottom

Question 2

reactions of metal with water

Answer 2

metals when reacted with water produce a metal hydroxide and hydrogen the more reactive a metal the faster the reaction

Question 3

reactioon of acids equation

Answer 3

acid+metal=salt+hydrogen

Question 4

what happens when an acid reacts with an alkali

Answer 4

neutralisation takes place salt and water produced

Question 5

reaction with base acid

Answer 5

acid+_metal oxide=salt+water

Question 6

reactions with carbonate

Answer 6

acid+carbonate=salt+water+carbon dioxide

Question 7

PH scale

Answer 7

in aqueous solutions acids produce H+ ions and alkalis produc OH- ions. neutral solutions are PH7 and neither acid or alkali

Question 8

making soluble salts

Answer 8

1. make a saturated solution by stiring copper oxide into sulfuric acid until no more dissolve
2. filter the solution to remove excess copper oxide solid
3. half fil a beaker with water and set this over a bunsen burner to heat the water place evaporating dish on top of the beaker
4. add some of the solution to the evaporating basin and heat until crystals form
5. once cooled pour the remaining liquid into a crystalising dish and leave to cool for one hour
6. remove crystals with a spatula and pat dry between paper towel

Question 9

process of electrolosis

Answer 9

is the splittingof an ionic substance using electricity

Question 10

using electrolosis to extract metals

Answer 10

metals are extracted by electrolosis if the metal in question reacts with carbon or if to reactive to be extracted by reduction with carbon during the extraction process large quantitys of energy are used to melt the compound

Question 11

electrolosis lead bromine

Answer 11

is an ionic substance when acid not able to conduct electrically when molten or in solution the ions are free to move and cary a charge

Question 12

posotive lead ions

Answer 12

are attractedtoard the negative cathode at the same time the negative bromine ions are atractid to the positive anode

Question 13

lead ions

Answer 13

attracted toards the negative electrode where the lead ions reacg cathode each ion gains two electrons becomes a neutral atom lead ions have been reduced

Question 14

bromine ions

Answer 14

attracted to the posotive electrode when bromine ions reach anode each looses one electron to become a neutral atom two bromine atoms are then able to bond ootgether to form covalent molecule

Question 15

electrolisis of aqueous solution

Answer 15

gases may have ben given of or metals deposited at the electrodes this is dependant on the reactivity of elements involved if the metal is more reactive than hydrogen then hydrogen will be produced at the negative cathode at the positive anode negatively charged ions loose electrons this is called oxidation you say ions have been oxidised

Question 16

posotive elctrode callecd

Answer 16

anode

Question 17

negative electrode called

Answer 17

cathode