group 1 (alkali metals) and group 2 (alkaline earth metals)
1 of 25
what is the trend of metallicness?
more metallic down group and from right to left. So most metallic are at bottom of group 1
2 of 25
why are the s-blocks used as compounds and not as metals in industry?
because theyre soft, low mp/bp and too reactive with oxygen and water
3 of 25
what is the first ionisation enthalpy?
the energy needed to remove on electron from every atom in 1M of gaseous atoms of an element
4 of 25
whats the general equation for the 1st I.E?
X(g) ---> X+ (g) + e-
5 of 25
which elements have the highest 1st I.E? Why?
noble gases, unreactive so hard to ionise
6 of 25
which elemetns have the lowest 1st I.E?
group 1, only one outer electron so easy to ionise
7 of 25
which three things affect the size of the ionisation enthalpy?
atomic radius (furhter from nucleus=less attraction=lower enthalpy) , shielding (more shileding=less attraction=lower enthalpy) and nuclear charge (less protons=less attraction=lower enthalpy)
8 of 25
which two trends can be found across the periodic table in regards to I.E?
decreases down a group (inc. atomic radius, shielding ) and increases across a period (more protons so more nuclear charge, less electron shielding)
9 of 25
why are there small drops between group 2 and 3?
boron has an outer electron in a 2p orbital, beryllium has its in a 2s orbital. the s sub shell is lower in energy so less energy is needed to ionise boron, depsite inc nuclear charge
10 of 25
why is there a decrease between nitogen and oxygen?
in oxygen, the electron being emoved is from a pair, thi sextra repulsion from the other electron means there's less energy needed to remove it.
11 of 25
whats the equation for the second ionisation enthalpy?
X+ (g) --->X2+ (g) + e-
12 of 25
is the second I.E the amount of energy needed to remove two electrons from an atom?
no, it's the amount of energy needed to remove one electron from an X+ atom
13 of 25
are group 2 reactive?
yes
14 of 25
give an equation showing group 2 metals reacting with oxygen
2M(s) + 02 (g) ---> 2MO (s)
15 of 25
give an equation showing group 2 metals reacting with water
M(s) + 2H20 (l) ---> M(OH)2 (aq) + H2 (g)
16 of 25
what equation shows the thermal decomposition of group 2 carbonates?
MCO3 (s) ----> MO(s) + CO2 (g)
17 of 25
why si the thermal decomposition of calcium carbonate important?
used to manufacture calcium oxide (quicklime)
18 of 25
why does thermal stability increase down group 2?
cations with high charge density (top of group) can distort or polarise the charge cloud around the carbonate ion, making it less stable and easier to break down with heat
19 of 25
whats the general formula for group 2 oxides and group 2 hydroxides?
MO and M(OH)2
20 of 25
what happens to group 2 oxides and hydroxides in water?
they're not very soluble but form alkaline solutions
21 of 25
give an equation showing a metal oxide reactig with an acid
MO+2HCl--->MCL2 (aq) + H2O
22 of 25
give an equation showing a metal hydroxide reacting with an aicd
M(OH)2 + H2SO4--->MSO4 + 2H2O
23 of 25
why do farmers add calcium hydroxide to their soils?
neutralsie soil acidity
24 of 25
whats the trend of a) reactivity with water b) pH of hydroxde in water c) solubility of hydroxide d) solubility of carbonate going down group 2?
a) more reactive b) more alkaline c) more soluble d) less soluble
25 of 25
Other cards in this set
Card 2
Front
what is the trend of metallicness?
Back
more metallic down group and from right to left. So most metallic are at bottom of group 1
Card 3
Front
why are the s-blocks used as compounds and not as metals in industry?
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