2.6 REVERSIBLE REACTIONS, INDUSTRIAL PROCESSES AND IMPORTANT CHEMICALS Flashcards
WHAT REACTS TOGETHER TO FORM AMMONIA?
Nitrogen and Hydrogen
WHAT IS A REVERSIBLE REACTION?
A rection that can go forwards and backwards
IS THE FORWARD REACTION IN THE HARBOUR PROCESS EXO OR ENDO?
Exothermic
WHAT IS THE FORMULA FOR AMMONIA?
NH3
WHAT TEMPERATURE PRODUCES A HIGH PRODUCT YEILD IN EXO REACTIONS?
Low temperature
WHAT TEMPERATURE PRODUCES A HIGH PRODUCT YEILD IN ENDO REACTIONS?
High temperature
WHAT ARE THE CONDITIONS IN THE HARBOUR PROCESS?
- Temp between 350 and 450
- Iron catalyst (to compensate for low temp)
- high pressure of 150-200 atmospheres
HOW ARE AMMONIA FERTILISERS MADE?
ammonia is neutralised in reactions with acids
WHAT ARE THE EQUATIONS FOR NEUTRALISING AMMONIA?
Ammonia + sulfuric acid ➔ ammonium sulfate
2NH3 + H2SO4 ➔ (NH4)2SO4
Ammonia + nitric acid ➔ ammonium nitrate
NH3 + HNO3 ➔ NH4NO3
WHAT IS THE TEST FOR AMMONIA GAS?
1) heat up the solution with some sodium hydroxide solution
2) The gas produced turns damp red litmus paper blue
WHAT ARE THE THREE STAGES OF THE CONTACT PROCESS?
Stage 1: Sulfur burns in the air to form sulfur dioxide gas.
stage 2: Sulfur dioxide reacts further with oxygen to make sulfur trioxide gas. This is a reversible reaction.
Stage 3: the sulfur trioxide is dissolved in concentrated sulfuric acid to produce a chemical called oleum.
WHAT CONDITIONS ARE NEEDED FOR STAGE 2 OF THE CONTACT PROCESS?
- a temperature in the range of 400–500oC
- an atmospheric pressure (1 atm)
- a vanadium(V) oxide V2O5 catalyst.
WHAT ARE THE THREE EQUATIONS OF THE CONTACT PROCESS?
sulfur + oxygen ➔ sulfur dioxide
S(s) + O2(g) ➔ SO2(g)
sulfur dioxide + oxygen ⇋ sulfur trioxide
SO2(g) + O2(g) ⇋ SO3(g)
sulfuric acid + sulfur trioxide ➔ oleum
H2SO4 + SO3 ➔ H2S2O7
WHAT ARE THE USES OF SULFURIC ACID?
Fertilisers, detergents, paint, polymers and paper
