Topic 2 Chemical changes

what is hydroxide, nitrate, sulfate, carbonate

polyatomic ions OH NO SO CO

OH^-

NO3 ^-

SO4 ²-

CO3 ²-

halogens

.7

all end with 2 (02, H2)

(ends with gen)

hydrogen

nitrogen

oxygen

(group 17)

fluorine

chlorine

bromine

iodine

need to know element subscripts

Iron (Fe)- Fe²+ OR Fe³+

Copper (Cu)- Cu+ OR Cu²+

Zinc (Zn)- Zn²+

Silver (Ag)- Ag+

Lead (Pb)- Pb²+ OR Pb4+

What are acids

-Acids are substances that dissociate in water to form hydrogen ions

properties of acids

Sour taste

<pH7

good conductors of electricity

where DO and do acids NOT show their properties

-show their properties in water

-dont show their properties in organic solvents

acid + reactive metal makes

salt and hydrogen

acid + carbonate makes

salt + water + CO2

what is acid + base called, what does it make

neutralisation

salt + water

3 need to know acids

Sulfuric acid (H2SO4)

Hydrochloric acid (HCl)

Nitric acid (HNO3)

What are bases and their properties

substances that react with acids to form salt and water

bitter, good conductors of electricity

(metal oxide or hydroxide)

what are alkalis and their properties

group 1 metal oxides or hydroxides

soluble in water

alkaline

properties of group 2-14 bases

insoluble in water

3 need to know acids’ salts

HCl- chloride

H2SO4- sulfate

HNO3- nitrate

how do we make salts

anion + cation

acid + metal ion of other

4 types of chemical reactions

synthesis

oxidation of metals

combustion

decomposition

synthesis definition

two or more substances combine to form a more complex substance (A+B=C)

combustion definition

substance reacts with oxygen to produce products and heat

(A + O2 = B + Heat)

oxidation of metals definition

metallic elements react with oxygen to form a metal oxide (A + O2 = AO2)

decomposition definition

substance breaks down to form 2 or more simpler substances (c = A + B)

water, ammonia, methane formula

H2O NH3 CH4

are co2 o2 h2 and nh3 odourless and colourless

co2 o2 h2

yes yes

nh3

yes pungent

pH of co2 o2 h2 and nh3

co2 acidic

o2 h2 neutral

nh3 alkaline

confirmatory test for co2

add gas to limewater

white precipitate formed when co2 bubbled into limewater

confirmatory test for oxygen

lighted splint test

lighted splint reignited

confirmatory test for hydrogen

lighted splint test

extinguished with a pop sound

universal indicators level

red-acidic

orange

green-neutral

blue

purple-alkaline