Section 2 Elements Of Life Flashcards
(18 cards)
Dilution Formula?
C1×V1= C2×V2
Colour change in acidic conditions for:<br></br>Methyl orange:<br></br>Phenolphthalein:
Methyl Orange: yellow to red
Phenolphthalein: pink to colourless
Shape of:s orbital,
p orbital, d orbital
s orbital: spherical
p orbital: dumbbell
d orbital: four leaf clover
Define the trend for first ionisation enthalpy down group 2 and explain.
Decreases down group as less attraction between outermost electrons and nucleus as size of atom increases.
Trend for first ionisation enthalpy across period 3 and why?
First ionisation enthalpy increases across a group. Because nuclear charge increases so outermost electrons are more attracted to the nucleus.
Solubility trend for group 2 hydroxides and carbonates?
Hydroxides: solubility increases down group
Carbonates: solubility decreases down group
What happens to group 2 oxides in water?
React with water to form metal hydroxides, which dissolve. The OH- ions makes the solution very alkaline, meaning they neutralise acids.
What are the soluble salts?
Potassium
Lithium
Ammonium
Nitrates
Sodium
Halides (except silver and lead halides and copper iodide).
Group 2 hydroxides and ammonium hydroxides.
Lithium, sodium, potassium and ammonium carbonates.
Sulfates except lead barium and calcium
Flame Test Colour for:<br></br>Lithium?<br></br>Sodium?<br></br>Potassium?<br></br>Calcium?<br></br>Barium?<br></br>Copper?
Lithium: red
Sodium: yellow
Potassium: lilac
Calcium: brick red
Barium: green
Copper: blue-green
NaOH ppt colour for following ions:<br></br><br></br>Silver: brown<br></br><br></br>Calcium: white<br></br><br></br>Copper(II): blue<br></br><br></br>Lead(II): white<br></br><br></br>Iron(II): green<br></br><br></br>Iron(III): brown <br></br><br></br>Zinc: white redissolves in excess NaOH to colourless<br></br><br></br>Aluminium: white redissolves in excess NaOH to colourless<br></br><br></br>
NaOH ppt colour for following ions:
Silver: brown
Calcium: white
Copper(II): blue
Lead(II): white
Iron(II): green
Iron(III): brown
Zinc: white redissolves in excess NaOH to colourless
Aluminium: white redissolves in excess NaOH to colourless
Test for carbonates?
Dilute HCl will make carbonates fizz because they give off CO2. You can test for CO2 as it turns limewater cloudy
Test for sulfates?
Add dilute HCl followed by barium chloride solution. If white ppt forms= sulfate
How to test for:<br></br>Ammonium?<br></br>Hydroxides?
Ammonium: add NaOH and gently heat. Ammonia gas will be given off turning damp red litmus paper blue.
Hydroxides: dip red litmus paper into solution. It will turn blue if hydroxide is present.
Test for halides?
Add silver nitrate:
Chloride: white ppt
Bromide: cream ppt
Iodide: yellow ppt
Test for nitrates?
Warm solution with NaOH and devarda’s alloy. If nitrates present ammonia gas will be given off, turning damp red litmus paper blue.
Describe the: <br></br>Absorption spectra<br></br><br></br>Emission spectra
Absorption: dark lines on coloured background
Emission: bright lines on dark background
Equation for difference in energy of 2 shells?
E= hv
E= difference in energy between two shells
h= planck’s constant( 6.63×10×-34 JHz-1)
v = frequency in Hz
Equation to find wavelength or frequency
C = v × λ
C = speed of light (m/s)
v = frequency (Hz)
λ = wavelength (m)
