Chemistry Term 1

mass of a reaction

sum of reactants = sum of products

enthalpy

energy required to break bonds

paper chromatography

used to separate substances with different solubilities

retention factor

distance travelled by substance/distance travelled by solvent

retention factor

is always less than 1

crystallisation

used to obtain a solid dissolved in a substance

process of crystallisation

heat the solution until it becomes saturated and till the saturation point. if crystals form on a glass rod, it is saturated. place the glass rod inside till the solid crystallises and the solution cools. wash the crystal to remove impurities

simple distillation

separate a liquid and soluble solid

process of simple distillation

the solution is heated to the boiling point of the liquid. the liquid evaporates, leaving the soluble solid inside

fractional distillation

used to separate liquids with different boiling points

process for fractional distillation

heat the solution to the lowest boiling point of a liquid. it will evaporate and get extracted through the condenser in the flask. repeat the process until all liquids are retracted separately.

filtration

undissolved solid from solution

test for ammonia

turns red litmus paper blue

test for carbon dioxide

turns lime water milky

test for chlorine

bleaches blue litmus paper white

test for hydrogen

burns with a loud squeaky pop

test for oxygen

reignites a glowing splint

flame test for lithium

red

flame test for sodium

yellow

flame test for potassium

lilac

flame test for calcium

orange-red

flame test for copper

blue-green

colour of bromine

reddish brown

colour of chlorine

pale green

colour of iodine

grey, purple fumes