C3.4 Analysis and Synthesis Flashcards
Flame colour of lithium
crimson
Flame colour of sodium
yellow
Flame colour of potassium
lilac
Flame colour of calcium
red
Flame colour of barium
green
What metal ions form a white precipitate when reacted with sodium hydroxide?
aluminium, calcium or magnesium
Flame colour of magnesium
no colour
What colour precipitate is formed when sodium chloride reacts with copper?
blue
What colour precipitate is formed when sodium chloride reacts with iron(II)?
green
What colour precipitate is formed when sodium chloride reacts with iron(III)?
brown
Dilute acid +carbonate
= carbon dioxide (limewater cloudy)
When you react nitric acid, silver nitrate solution and chlorine, what colour precipitate is there?
white
When you react nitric acid, silver nitrate solution and bromide, what colour precipitate is there?
cream
When you react nitric acid, silver nitrate solution and iodide, what colour precipitate is there?
pale yellow
How do you test for sulphate ions?
add HCl and barium chloride solution a white precipitate is formed for sulphate ions
What is equilibrium?
the point in a reversible reaction in which the forward and backward rates of reaction are the same
In equilibrium, if the forward reaction produces more moles of gas….
an increase in pressure decreases the amount of products formed, a decrease in pressure increases the amount of products formed
In equilibrium, if the forward reaction produces fewer molecules of gas…
an increase in pressure increases the amount of products formed, a decrease in pressure decreases the amount of products formed
In euilibrium if the forward reaction is exothermic…
an increase in temp decreases the amount of products formed
in equilibrium, if the forward reaction reaction is endothermic…
an increase in temp increases the amount of product formed, a decrease in temp decreases the amount of products formed
Why is nitrogen lost in plants?
roots absorb nitrates and die and release the nitrate so farmers need to put nitrate in soil every year
When making ammonia, where does nitrogen come from?
the air
When making ammonia, where does hydrogen come from?
natural gas (methane) and steam
What process is used when making ammonia?
the haber proccess
What happens in the Haber process?
the elements are passed over an iron catalyst at 450 degrees and 200 atmospheres
Why is the pressure not higher?
lots of energy to compress, expensive, explosion
why do we use a catalyst?
Speeds up forward and backward so we get more ammonia quicker
