4-chemical changes

Question 1

method to produce pure dry sample of soluble salt copper chloride from acid and metal oxide

Answer 1

1. react hydrochloric acid with copper oxide
2. warm conditions + suitable container
3. add copper oxide in excess, stir
4. filter off excess powder
5. pour filtrate into evaporating basin
6. use water bath to heat gently
7. when u heat it all the stuff goes away to leave pure substance
8. leave to cool/crystallise

Question 2

what is reduction=

Answer 2

gain of electrons
Oxidation
Is
Loss
Reduction
Is
Gain

Question 3

what is oxidation

Answer 3

loss electrons

Question 4

during electrolysis what happens at the negative electrode

Answer 4

reduction, ions gain electrons

Question 5

oxidation of chloride equation

Answer 5

2CL——> Cl2+ 2e-

Question 7

what do metals want to do

Answer 7

react
lose e
full outtershell
form+ ions

Question 8

the more reactive a metal is the more…

Answer 8

vigorous reaction
easily loses e- -> ions

Question 9

what are + ions called

Answer 9

cations

Question 10

most reactive metals

Answer 10

K, Na, Li,Ca,Mg

Question 11

least reactive metals

Answer 11

Zn, Fe, Cu

Question 12

metal+ water

Answer 12

metal hydroxide+ hydrogen
solid. liquid. g

Question 13

observations when lithium is placed into water with universal indicator

Answer 13

fizzing= hydrogen gas
blue-purple= hydroxide alkaline

Question 14

metal+ acid

Answer 14

MASH
metal+acid - salt + hydrogen

Question 15

magnesium + hydrochloric acid

Answer 15

Mg + HCL -> MgCl + H2