CHEM 101: Lab Exam Questions and
Answers with Complete Solutions |
New Update 2026
What type of spectrum is emitted by gaseous discharge tubes? - ANSWERS A
discontinuous spectrum
White light from the sun emits what type of spectrum? - ANSWERS A
continuous spectrum from red to violet
How are photons emitted in discharge tubes? - ANSWERS As the excited atom
returns to a lower energy state, photons are emitted
What are 3 common applications of light emission by elements? - ANSWERS 1)
The flame test
2) Fireworks
3) Office fluorecent lights
The spectrometer gets data on ________________ - ANSWERS absorption
The plot of _______________ against ___________________ of incident light is
called a spectrum - ANSWERS Absorption, wavelength
The shorter the wavelength the _____________ the energy - ANSWERS higher
,Transitions with the smallest energy change will have the longest wavelength,
explain why this is? - ANSWERS This is because energy is inversely
proportional to wavelength
What are the two posssible reasons for an object to show a particular colour? -
ANSWERS 1) THe absorbance of all wavelengths but those of said colour
2) THe absorbance of the complimentary colour
Why did the smarties show the colour they did? - ANSWERS Because they
absorbed the complimentary colour
What is the main ore of Al? What is it composed of? - ANSWERS The main ore
of Al is bauxite, a hydrate of Al2O3, mixed with oxides of iron, silicon, and titanium
What are the two ways you can recycle scrap aluminum? - ANSWERS By
melting it or a chemical reaction
Al(OH)3 is atmospheric, what does this mean? - ANSWERS It can react either
with an acid or with a base
What does a fertilizer label of 10-20-20 means - ANSWERS The guaranteed
percent nitrogen, phosphoric acid, and potash in the fertilizer
What are the other products of the reaction that creates Cu(NO3)2? -
ANSWERS NO and H2O
, On exposure to air, what happens to NO - ANSWERS It forms NO2 and
becomes a posonus reddish brown gas
What is the filtrate? - ANSWERS The liquid that passes through the filter into
the filter flask
Efflorescent - ANSWERS Hydrates that spontaneously lose water to the
atmosphere
How does efflorescence occur? - ANSWERS This loss of water occurs because
the vapor pressure of water exerted by efflorescent solids is greater that that of
the vapor pressure of water in the surrounding atmosphere
Hygroscopic - ANSWERS Hydrates that spontaneously absorb water from the
atmosphere
Why may Hygroscopic hydrates, that spontaneously absorb water from the
atmosphere, be termed dessicates? - ANSWERS Because they are used a dry
liquid/gas
Deliquescent - ANSWERS When a compound absorbs water from the
atmosphere so strongly that it dissolves in its own hydration
How do you go about removing water of crystilization from a hydrate that is stable
at room temperature? - ANSWERS It must be heated to a temperature at
which the vapour pressure of the water exerted by the solid hydrate exceeds the
partial pressure of water in the atmosphere above the solid
Answers with Complete Solutions |
New Update 2026
What type of spectrum is emitted by gaseous discharge tubes? - ANSWERS A
discontinuous spectrum
White light from the sun emits what type of spectrum? - ANSWERS A
continuous spectrum from red to violet
How are photons emitted in discharge tubes? - ANSWERS As the excited atom
returns to a lower energy state, photons are emitted
What are 3 common applications of light emission by elements? - ANSWERS 1)
The flame test
2) Fireworks
3) Office fluorecent lights
The spectrometer gets data on ________________ - ANSWERS absorption
The plot of _______________ against ___________________ of incident light is
called a spectrum - ANSWERS Absorption, wavelength
The shorter the wavelength the _____________ the energy - ANSWERS higher
,Transitions with the smallest energy change will have the longest wavelength,
explain why this is? - ANSWERS This is because energy is inversely
proportional to wavelength
What are the two posssible reasons for an object to show a particular colour? -
ANSWERS 1) THe absorbance of all wavelengths but those of said colour
2) THe absorbance of the complimentary colour
Why did the smarties show the colour they did? - ANSWERS Because they
absorbed the complimentary colour
What is the main ore of Al? What is it composed of? - ANSWERS The main ore
of Al is bauxite, a hydrate of Al2O3, mixed with oxides of iron, silicon, and titanium
What are the two ways you can recycle scrap aluminum? - ANSWERS By
melting it or a chemical reaction
Al(OH)3 is atmospheric, what does this mean? - ANSWERS It can react either
with an acid or with a base
What does a fertilizer label of 10-20-20 means - ANSWERS The guaranteed
percent nitrogen, phosphoric acid, and potash in the fertilizer
What are the other products of the reaction that creates Cu(NO3)2? -
ANSWERS NO and H2O
, On exposure to air, what happens to NO - ANSWERS It forms NO2 and
becomes a posonus reddish brown gas
What is the filtrate? - ANSWERS The liquid that passes through the filter into
the filter flask
Efflorescent - ANSWERS Hydrates that spontaneously lose water to the
atmosphere
How does efflorescence occur? - ANSWERS This loss of water occurs because
the vapor pressure of water exerted by efflorescent solids is greater that that of
the vapor pressure of water in the surrounding atmosphere
Hygroscopic - ANSWERS Hydrates that spontaneously absorb water from the
atmosphere
Why may Hygroscopic hydrates, that spontaneously absorb water from the
atmosphere, be termed dessicates? - ANSWERS Because they are used a dry
liquid/gas
Deliquescent - ANSWERS When a compound absorbs water from the
atmosphere so strongly that it dissolves in its own hydration
How do you go about removing water of crystilization from a hydrate that is stable
at room temperature? - ANSWERS It must be heated to a temperature at
which the vapour pressure of the water exerted by the solid hydrate exceeds the
partial pressure of water in the atmosphere above the solid
