ammonia Flashcards
state the observation
burning of ammonia in air
a greenish-yellow flame is observed
state the observation
when ammonia is burnt in an atmosphere of excess oxygen
ammonia burns with a pale blue flame in the atmosphere of excess oxygen
state the observation
excess of chlorine gas is reacted with ammonia gas
a yellow explosive liquid is formed (nitrogen trichloride)
state the observation
ammonia is passed through the copper oxide
black copper oxide changes to red copper
state the observation
excess of ammonia is passed through an aqueous solution of lead nitrate
a white precipitate is produced which is insoluble even in an excess of ammonia
state the observation
a piece of moist red litmus paper is placed in a gas jar of ammonia
it turns blue
state the observation
neutral litmus solution is added to an alkaline solution
it turns blue
this gas is used as a reducing agent in reducing copper oxide to copper
ammonia
gas produced when excess ammonia reacts with chlorine
nitrogen
alkaline gas which gives dense white fumes with HCl
ammonia
the gas that can be oxidized to sulphur
hydrogen sulphide
an oxidizing agent which does not contain any sulphur
chlorine gas
warming ammonium sulphate with sodium hydroxide solution
ammonia
drying agent used to dry ammonia
CaO
passing dry ammonia over heated copper oxide gives ______
copper
ammonia can be obtained by adding water to _______
magnesium nitride
ammonium nitrate is used in ___________________
preparing explosives
with excess of chlorine what does ammonia form
NCl3 [nitrogen trichloride]
why is liquid nitrogen employed in refrigerator
because it has a high latent heat of vaporization so it takes high amount of heat from the surroundings resulting in the fall of temperature
why is ammonia soluble in water
this is because it is a polar molecule
nesseler’s reagent is an alkaline solution of _____
K2HgI4 [Potassium tetraiodomercurate(II)]
what temperature is catalytic oxidation of ammonia carried out at ?????
800 degrees celcius
where is the nitrogen used in haeber’s process obtained from
fractional distillation of air
how is ammonia gas collected
downward displacement of air
why is ammonia used as a cleaning agent
ammonia solution emulsifies fat and grease so that they can be removed without leaving any residue
ammonia solution is used as a laboratory reagent to identify metal ions
aqueous solution of ammonia can precipitate insoluble hydroxide of metals from their salt solutions
hence it is used in the analytical analysis of the salts in the labaratory
ammonia is present in sewage water
this because ammonia is produced due to bacterial decomposition of urea [NH2CONH2] present in urea
solution of ammonia contains hydroxide ions
since ammonia turns red litmus solution blue
it reacts with water to form salt and water
ammonia cannot be collected over water
ammonia is extremely soluble in water and cannot be collected over water
though ammonia nitrite readily gives nitrogen on heating,
a mixture of ammonium chloride and sodium nitrite in water is heated to prepare nitrgoen in the labaratory
ammonium nitrite cannot be stored even at room therefore nitrogen is obtained by heating ammonium chloride and sodium nitrite
magnesium nitride reacts with water to liberate _____ and _________
ammonia and magnesium hydroxide
what is labaratory bench reagent
it is a dilute solution of liquor ammonia
why is dry or liquid ammonia neutral to litmus
ammonia is a covalent compound therefore in the absence of ions dry or liquid Ammonia has no effect on litmus
state the purpose of liquifycing ammonia produced in haeber’s process
the ammonia procuced is liquifiedto seperate it from uncombined nitrogen and hydrogen
write the equation for Haeber’s process that forms ammonia
N2 + 3H2 –> 2NH3 (reversible)
{200-900atm and 450-500 degrees celcius and catalyst Fe and Mo}
what test does Nessler’s reagent give with ammonium salts
when ammonium compound is added to colourless Nessler’s reagent a brown colour is observed
why is acidic drying agent not used for drying ammonia
because acidic drying agents such as H2SO4 react with ammonia
how does the solubility of ammonia vary with its temperature
its solubility decreases with an increase in temperature
how will you separate ammonia from uncombined N2 and H2
by liquefication
by dissolving in water
why is catalyst chamber provided with a heat exchanger
this is so that the outgoing ammonia gas and the unreacted gases exchange their heat with the incoming nitrogen and hydrogen
which is more dense, ammonia or hydrogen chloride
how is it collected
hydrogen chloride is denser than ammonia
upward displacement of air
what happens when ammonia and HCl gas react
write the equation
NH3 + HCl –> NH4Cl
give 2 evidences to show that the solution of ammonia in water contains hydroxide ions
i) solution of ammonia is alkaline towards litmus
ii) the solution of ammonia precipitates insoluble metal
hydroxide
what is the reactant used in the preapration of ammonia gas
Mg3N2 + H2O
what is the drying agent used in the preparation of ammonia gas
quicklime (Cao)
what is the method of collection used in the preparation of ammonia gas
downward displacement of air
large scale use of ammonia
manufacture of nitric acid by ostwalds process
what properties of ammonia make it a source of hydrogen
–> ammonia can be liquified and transported easily and on decomposition gives hydrogen
–> liquid hydrogen is dangerous to transport in cylinders
how is ammonium chloride prepared
neutralisation
when ammonium chloride is heated what reaction does it undergo
thermal dissociation
what does heating ammonia chloride with sodium hydroxide produce
ammonia
why is ammonia nitrate not used in the preparatuon of ammonia
- -> it is explosive in nature
- -> it decomposes giving nitrous oxide and water vapour
how do you find out if the jar is full of ammonia gas
bring a rod dipped in HCL to the mouth of the jar for which ammonium chloride will be formed
