Preparation Of Gases Flashcards
What is the molecular mass of air?
28.8
What kind of collection do gases undergo based on their density?
Upward delivery aka Downward displacement of air
What kind of collection do heavier gases undergo
Downward delivery aka Upward displacement of air
What are drying agents?
substances that absorb moisture from a prepared gas
Mention three eg of drying agents
Silica gel, CaO,H2SO4, CaCl2
Define catalysts
These are substances that speed up a reaction without taking part in it.
Mention two eg of catalysts
CuSO4,nickel catalyst
Briefly describe how to prepare hydrogen gas.
Dilute HCl is added to zinc metal in a flat-bottomed flask.
to speed up the reaction, CuSO4 is added
the gas is collected using upward delivery
What is the equation for preparing H2?
2HCl + Zn = H2 + ZnCl2
Mention 4 uses of hydrogen gas
Rocket fuel
hardening of oil in the production of margarine
filling balloons
manufacturing ammonia in the Haber process
used in oil refinery
converting coal to petrol
manufacturing methanol
Mention 4 properties of hydrogen gas
less dense than air
insoluble in water
colourless and odourless
burns readily in air to form water
doesnt support combustion
burns in oxygen to produce hydrochloric acid
makes a pop sound when exposed to air
reducing agent
How is ammonia gas prepared in the laboratory?
take any ammonium salt and a base i.e NH4Cl and Ca(OH)2
grind the two substances into powder
place the mixture in a round bottomed flask whose neck must be sloped downwards
the flask is heated and gives off NH3
NH3 passes through a U-Tube with CaO to dry
upward delivery
Why are the substances used in the creation of NH3 grounded?
For a faster reaction
Why is the neck of the round bottomed flask titled when creating NH3 gas?
This is to prevent the heated liquid from returning into the flask, which may in turn break the glass
What is the equation for the preparation of NH3?
2NH4Cl + Ca(OH)2 =2NH3 + 2H2O + CaCL2
