Acids Bases And Salts Flashcards
Why do crystals form on cooling hot saturated solution
When solution is hot, solubility is higher as it cools solubility decreases and crystals start to form
Why is all the water not simply evaporated off the solution
Many salts , contain water of crystallisation so water is locked into the crystal structure of the salt during crystallisation
Metal + acid -> metal salt + hydrogen
General observations
Fizzing
Metal disappears
Heat given out
Colourless solution formed
Test for hydrogen
Lit splint gives sqeuky pop, the hydrogen is burning in the air to produce water
2H2 + O2 -> 2H2O
Metal carbonate/hydrogen carbonate+ acid -> carbon dioxide + water + metal salt
Observations
Fizzing
Solid disappears (give colour)
Heat given out (bar sodium hydrogen carbonate)
Colourless (blue if copper salt) solution formed
test for carbon dioxide
Bubble through lime water ( calcium hydroxide solution)
Colourless to milky
Alkali/base + acid -> salt + water
Observations, what’s is also an alkali
Ammonia solution
Heat given out ( bar copper oxide )
If solid : some (colour) solid disappears
Colourless ( blue if copper salt solution formed )
1 what observation if gas is produced
2 what observation if one reactant is a solid
3 what observation if insoluble
4 what are the exception to heat given out
5 what is soluble
1 Bubbles
2 (colour) soli disappears, (colour) solution is produced
3 metal disappears
4 copper(II) oxide , sodium hydrogen-carbonate
5 liquids
Give colour
1acids at start
2 copper oxide
3 copper carbonate
4 solutions of copper salts
5 oxides and other compounds of group 1,2 and aluminium
6 solutions of group 1, 2 and aluminium compounds
1 colourless
2 black
3 green
4 blue
5 white
6 colourless
Exothermic
Gives out heat to surroundings
Endothermic
Reaction takes in heat from surroundings
Corrosive
Risk and precaution
May cause burns to skin
Damage eyes
Corrode metals
Wear gloves and safety glasses
Acutely toxic
Risks and precautions
If ingested could belief threatening
Wear gloves and safety goggles
Use fume cupboard
Flammable
Risk and precaution
Goes on fire easily when exposed to spark
Keep away from naked flame
Explosive
Risks and precautions
Can explode easily form fire/ heat struck
Keep away from explosive sources
Moderate hazard
Risk and precautions
May irritate skin
Wear safety goggle and gloves
How can you tell if all the acid has been neutralised
When some solid remains at the bottom, Un reacted
If carbonate (or metal) is used there will be no more bubbles of gas
Why is excess solid added
To make sure that all the acid has been neutralised
It leaves a pure solution of salt after filtration
3 drying methods
Place in desiccator
Low temperature oven
Between 2 sheets of filter paper
Spell indicator that goes form pink in alkali to colourless in solution
Phenolphthalein
How to prepare pipette
Rinse with deionised water
Using pipette filler rinse with solution
Fill with solution
Hold the pipette vertically with the volume line at eye level
Run out the solution until the bottom of meniscus is on the line
How to prepare burette
Rinse with deionised water
Rinse with solution
Fill with solution
Allow the solution to run out until the bottom of the meniscus is at the 0 line
Ensure the tip is full and there are no air bubbles
Concentration (mol/dm3)
Th number of moles of a solid dissolved in 1dcm3 of solution
Salt
Compound formed hen some or all hydrogen ions in an acid are replaced by metal ions or ammonium ions
Strong acid/alkali
Ionise completely in solution
Weak acid/alkali
Ionise partially in solution
Phenolphthalein solution
1 acid
2 neutral
3 alkail
1 colourless
2 colourless
3 pink
Methyl orange solution
1 acid
2 neutral
3 alkali
1 red
2 orange
3 yellow
Blue litmus
1 acid
2 neutral
3 alkali
1 red
2 blue
3 blue
Red litmus
1acid
2nuetral
3alkali
1 red
2 red
3 blue
