chemical change

Question 1

what is word equation for sodium + oxygen

Answer 1

sodium + oxygen —> sodium oxide

Question 2

what is oxidation

Answer 2

gain of oxygen/ loss of electrons

Question 3

what is reduction

Answer 3

loss of oxygen/ gain of elections

Question 4

name all ions in reactivity series from most to least reactive (14) (5,5,4)

Answer 4

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

Question 5

what happens during a displacement reaction

Answer 5

the more reactive metal takes the place of a reactive metal in a compound or no change at all

Question 6

why does gold not need to be extracted from ores

Answer 6

unreactive

Question 7

what is used to extract unreactive metals from their ores

Answer 7

carbon

Question 8

word equation for carbon and a metal oxide

Answer 8

carbon +metal oxide —> carbon dioxide + metal

Question 9

what happens to metal and carbon when carbon is used to extract a metal from its ore

Answer 9

iron is reduced as it loses oxygen

carbon is oxidised as it gains oxygen

Question 10

wrote a half equation for a metal in a redox reaction using Na and Al

Answer 10

Na —> Na^+ .+. e^-

Al —> Al^3+ .+. 3e^-

Question 11

write a half equation for a non metal in a redox reaction using Br and O

Answer 11

Br2+ .+. 2e^- —> 2Br

O2 .+. 4e^- —>2O^-2

Question 12

what is a redox reaction

Answer 12

reaction where oxidation and reduction takes place

Question 13

word equation for reaction between a metal and acid

Answer 13

metal + acid —> salt + hydrogen

Question 14

what 3 compounds can neutralise an acid ( with examples )

Answer 14

alkalis (soluble metal hydroxides)
bases (insoluble metal hydroxides and oxides)
metal carbonates

Question 15

word equation for reaction of a metal hydroxides and acid

Answer 15

metal hydroxides + acid —> salt + water

Question 16

equation for metal oxide and acid

Answer 16

metal oxide + acid —> salt + water

Question 17

word equation for metal carbonate with acid

Answer 17

metal carbonate + acid —> salt + water + carbon dioxide

Question 18

what is the formula for chloride

Answer 18

Cl^-

Question 19

what is the formula for sulfate

Answer 19

SO4^2-

Question 20

what is the formula for nitrate

Answer 20

NO3^-

Question 21

what is the formula for carbonate

Answer 21

CO3^2-

Question 22

what is the formula for hydroxide

Answer 22

OH^-

Question 23

what is the first step in producing a salt from reactants

Answer 23

heat acid using a water bath

Question 24

what is the second step for producing salt from reactants

Answer 24

add solid until no more will dissolve in solution

Question 25

what is the third step for producing a salt from reactants

Answer 25

filter the solid from the solution using a funnel and filter paper

Question 26

what is the fourth step for producing a salt from reactants

Answer 26

crystallise the salt by heating to evaporate the water and leave out to evaporate fully

Question 27

symbol equation for the neutralisation reaction

Answer 27

H+ .+. OH- —> H2O